Health A-Z


Clinical Definition Abdominoplasty is an elective procedure to remove excess fat and abdominal skin while tightening weakened or separated stomach muscles. In Our Own Words An abdominoplasty flattens, firms and slims the abdomen by removing excess fat and skin while tightening muscles in the abdominal wall. It is a major elective surgery that requires general

ACE inhibitors

Clinical Definition ACE Inhibitors are a class of drugs that block the conversion of angiotensin I to angiotensin II, used in the treatment of hypertension and congestive heart failure, and in the prevention of microvascular complications of diabetes mellitus. In Our Own Words ACE inhibitors are medications that work by lowering the blood pressure and


Clinical Definition Acetaminophen is a crystalline compound classified as a non-opioid analgesic. It is also used as an antipyretic with a similar potency to aspirin. The exact mechanism of action of acetaminophen is not clear, but it does appear to inhibit the synthesis of prostaglandins. In large doses, acetaminophen can lead to acute hepatic toxicity.

Acetylsalicylic acid

Clinical Definition Acetylsalicylic acid, also known as aspirin, is classified as a non-steroidal anti-inflammatory pharmaceutical agent. It contains salicylic acid, the active metabolite that inhibits prostaglandins. Acetylsalicylic acid is used as an antipyretic and analgesic. It is also sometimes prescribed as antiplatelet agent in order to reduce the risk of a myocardial infarction and cerebrovascular

ACL Reconstruction

Clinical Definition One type of knee surgery involves reconstruction of the anterior cruciate ligament, or the ACL. The ACL is a band of connective tissue that provides stability to the knee. ACL injuries are very common, especially in sports that demand quick stops and starts or rapid changes in velocity, and are often treated surgically.

Acute Altitude Sickness

Clinical Definition Acute altitude sickness, also called mountain sickness, is a group of general symptoms triggered by traveling to a higher elevation, usually above 8,000 feet, too rapidly. The potentially life-threatening illness is due to reduced air pressure and lower oxygen levels. In Our Own Words Altitude sickness, also known as mountain sickness, occurs when

Acute coronary syndrome

Clinical Definition Acute coronary syndrome is an umbrella term for a group of coronary artery diseases associated with sudden blockage of the blood supply to the heart muscle. Acute coronary syndrome is a medical emergency. In Our Own Words Acute coronary syndrome is a medical emergency describing a group of conditions, including a possible heart


Clinical Definition Attention deficit hyperactivity disorder is a developmental and behavioral disorder characterized by inattention, hyperactivity, and impulsivity. While the exact causes have not been determined, research suggests that it has a strong neurobiological basis. Impairment of executive brain functions that activate, organize, integrate and manage relate to symptoms associated with ADHD. The disorder is

AED machine

Clinical Definition An AED machine is a portable medical device that can be used to treat life threatening arrhythmias, including pulseless ventricle tachycardia and ventricular fibrillation. The machine is programmed to analyze myocardial rhythms and if indicated, deliver a therapeutic dose of electrical energy to the heart. The electrical current depolarizes a critical mass of


Clinical Definition Acquired immune deficiency syndrome, most commonly called AIDS, is a serious infection caused by the human immunodeficiency virus or HIV. The body cannot get rid of HIV. There are treatments but there is still no cure. The virus is transmitted when an infected person’s bodily fluids, such as blood, semen, vaginal fluids or


Clinical Definition Alcoholism, also known as alcohol dependence or alcohol abuse, is a chronic, progressive disease characterized by excessive intake of alcohol, impaired control over drinking and compulsive drinking, despite known adverse consequences of the behavior. The onset of withdrawal symptoms occurs with cessation of use. Treatment begins with ”detox.” In Our Own Words Alcoholism


Clinical Definition An allergy is an abnormal or hypersensitive immune reaction to an allergen, a substance that is normally harmless, but that triggers an allergic response, including the release of the chemical histamine, which can cause reactions like sneezing or a rash. In Our Own Words If you have an allergy, or are allergic to

Alpha1-Antitrypsin Deficiency

Clinical Definition Alpha1-antitrypsin deficiency is a genetic disorder, which causes insufficient production of the blood protein alpha1-antitrypsin. The protein, which is manufactured in the liver, travels through the bloodstream and protects the lungs from the enzyme neutrophil elastase. The lack of alpha1-antitrypsin allows the enzyme to accumulate and damage the lungs. As a result, conditions


Clinical Definition Amblyopia is visual impairment in which the neural development for one eye is favored over the other. The vision in one eye thus becomes weaker, despite the absence of explanatory ocular abnormalities. Strabismus, commonly known as crossed eyes, is the most common cause. In Our Own Words Amblyopia, a common cause of vision


Clinical Definition Anemia is a blood disorder that occurs when a person does not have adequate hemoglobin, which transports oxygen through the body, via the blood. Anemia is frequently caused from a lack of iron, which the body uses to make hemoglobin. More serious types of anemia are sickle-cell anemia, which is an inherited disease


Clinical Definition An aneurysm is an abnormal dilation, ballooning or bulging of the wall of an artery. It develops at a site of weakness. While aneurysms are more common in adults than children, they can occur at any age. Small aneurysms generally are not accompanied by symptoms, but those with a larger aneurysm may report


Clinical Definition Angina, or chest pain, is the most common symptom of coronary artery disease. Caused by ischemia, angina is often due to a clot forming in a partially blocked coronary artery. Angina can be described as discomfort or heaviness in the chest. Too often, this acute and dangerous symptom is passed off as simple


Clinical Definition Angioedema is a non-pitting edema that affects the dermis and subcutaneous layers, most often involving the tongue, lips, face and throat, but also less commonly the genitalia and viscera. Edema can also affect the airway, a potentially life-threatening event. If angioedema is severe, emergency treatment to ensure an open, functioning airway is needed.

Anorexia nervosa

Clinical Definition Anorexia nervosa is a psychological eating disorder in which a person has an intense fear of gaining weight and limits calories to the point of near starvation to attain a below-normal body weight. In Our Own Words Individuals with anorexia nervosa suffer from a distorted body image, typically coupled with feelings of inadequacy

Anti-retroviral therapy

Clinical Definition Anti-retroviral therapy, or ART, is treatment with drugs that hamper the ability of the human immunodeficiency virus (HIV) or other types of retroviruses to replicate in the body. Combining several ART drugs, known as highly active ART or HAART, can reduce viral particles in the blood. In Our Own Words Anti-retroviral therapy or


Clinical Definition Blood thinners are prescription drug medications that diminish the blood’s ability to form clots. Regular blood monitoring is mandated when taking anticoagulant drugs, which may also reduce risk of stroke and irregular heartbeat. These medications may take 5 to 7 days to become fully active. In Our Own Words Sometimes referred to as


Clinical Definition Antihistamines inhibit the action of histamine, an important chemical in the body.  During seasonal or perennial allergic rhinitis, histamines are part of a cascade of events that leads to nasal blockage, discharge, sneezing, itch and postnasal drip. Antihistamines have an antagonistic action at the H1 or H2 receptor sites. The medication may cause


Clinical Definition Antioxidants are naturally occurring agents that prevent cellular oxidation, and may protect the body from molecules that damage cells (called free radicals). Common dietary antioxidants include vitamins A, C and E. In Our Own Words Antioxidants are natural or synthetic substances found in foods that may protect cells from the damaging effects of


Clinical Definition The aorta is the body’s largest artery. The left ventricle (chamber) of the heart pumps blood rich in oxygen through the aortic valve and into the aorta. From there, the aorta distributes blood to the general circulation. In Our Own Words The role of the largest artery of the human body, the aorta,

Aortic Insufficiency

Clinical Definition Aortic insufficiency is a cardiac valve condition in which the aortic valve fails to close properly during ventricular diastole. The leaky valve creates a regurgitant flow of blood back into the left ventricle. Due to the backwards blood flow, left ventricular pressure can increase, possibly leading to hypertrophy of the myocardium. In some


Clinical Definition Appendicitis is a common medical condition that involves inflammation of the appendix, usually due to a bacterial infection. Inflammation is thought to develop when stool, mucus or a parasite fills the interior of the appendix. In instances of acute appendicitis, if surgical intervention is delayed, complications such as peritonitis can develop. In Our


Clinical Definition Any abnormal heart rate or rhythm that affects specific parts of the heart is considered an arrhythmia. Classified according to origin, a ventricular arrhythmia occurs at the lower ventricle chambers of the heart, while supraventricular arrhythmias originate above the ventricles, or the upper (atrial) chambers of the heart. In Our Own Words Any


Clinical Definition Arthritis is acute or chronic inflammation of one or more joints, typically causing pain, stiffness, swelling, and sometimes loss of movement. The most common type of arthritis is osteoarthritis, but rheumatoid arthritis is also a common form of arthritis. In Our Own Words The word arthritis literally means joint inflammation, and is used

Asperger Syndrome

Clinical Definition Asperger syndrome (AS) is a neurodevelopmental disorder on the autistic spectrum. The condition is considered present from infancy. Individuals with Asperger syndrome may vary in clinical presentation. In general, the disorder may cause nonverbal communication difficulties, repetitive behavior, social impairment and problems with sensory input. In Our Own Words Asperger syndrome (AS), also


Clinical Definition Asthma is a chronic inflammatory disease of the lungs characterized by increased airway reactivity in response to certain stimuli. During an asthma exacerbation, constriction of the smooth muscle of the bronchi, increased mucus production and mucosal edema occur, which creates the clinical presentation of respiratory distress. In Our Own Words Asthma is a


Clinical Definition Asymptomatic is a medical term used to describe an individual who is a carrier of an infection or a disease, but is clinically silent or not experiencing symptoms. Asymptomatic conditions may cause a delay in the diagnosis of said infection or disease. Being asymptomatic does not indicate the seriousness of a condition. In


Clinical Definition Atelectasis is a partial lung collapse, or, less commonly, collapse of the entire lung. The cause is blockage of the bronchus or bronchioles or pressure outside the lung. Hospitalized patients and post-op patients are vulnerable. Symptoms include respiratory difficulty, cough, chest pain and low-grade fever. Treatments are aimed at relieving the blockage. In


Clinical Definition Atherosclerosis is an accumulation of plaque in the arterial walls, causing stenosis and sometimes leading to ischemia, with chest pain and myocardial infarctions, cerebral infarcts and vascular dementia. The origin is probably endothelial injury, with contributions from hypertension, hyperlipidemia, hyperhomocysteinemia, inflammation, obesity and sedentary lifestyle. Treatments include medication, lifestyle changes, surgery and other

Athlete’s Foot

Clinical Definition Athlete’s foot, or tinea pedis, is a contagious infection caused by a fungus that thrives in warm, moist environments. Symptoms include erythema, vesicles and burning. Diagnosis is by clinical exam, biopsy or examination of the skin culture. Treatment includes self-care with over-the-counter antifungal products, good hygiene or prescribing of antifungal medications. In Our


Clinical Definition Autism is the most common condition in a complex collection of developmental disorders known as the autism spectrum disorders (ASP). Those afflicted with this sometimes disabling and lifelong condition exhibit social, verbal and behavioral challenges. In Our Own Words Autism is a collection of behavioral disorders that affects individuals differently, depending on severity

Back Pain

Clinical Definition Back pain has numerous etiologies, with onset sometimes occurring after improper lifting or bending mechanics, and other times occurring due to spinal changes, such as intervertebral disc disorders. Disc injury, disc tears or herniation, spinal stenosis, scoliosis and other causes can trigger back pain, sometimes becoming chronic. Treatments include nonsurgical approaches (medication and

Bacterial Infection

Clinical Definition A bacterial infection is an illness due to pathogenic bacteria that gain entrance to the body through various means, including the digestive system, the respiratory system and the skin. Once inside the body, the bacteria reproduce, which may lead to various symptoms and illnesses. Bacterial infections are often treated with antibiotics. In Our

Bacterial Pneumonia

Clinical Definition Bacterial pneumonia is an acute or chronic infection of one or both lungs, with inflammation and varying degrees of fluid filling the air sacs (alveoli) causing respiratory dysfunction. Some types of pneumonia can be seen on chest x-ray as areas of density in the infected parts of the lungs. In Our Own Words

Bell’s Palsy

Clinical Definition Bell’s palsy is a paralysis of the facial muscles caused by damage such as swelling, compression, or inflammation to the seventh cranial nerve. An electromyography (EMG) can detect the presence and extent of nerve damage and may also help to predict the rate of recovery. A magnetic resonance imaging (MRI) test can rule


Clinical Definition Benign, the opposite of malignant, is often used to describe a tumor that is non-cancerous and typically does not metastasize. In Our Own Words In describing tumors, the term benign means “not malignant.” Benign tumors are growths that do not spread or take over like cancer does. While benign growths might be harmless,

Benign Prostatic Hyperplasia

Clinical Definition Benign prostatic hyperplasia or BPH is a condition marked by a non-cancerous proliferation of cells, both smooth muscle and epithelial, in the prostate gland’s transition zone. Lower urinary tract symptoms accompany the hyperplasia. Diagnosis is made by medical history, physical exam, and tests, including urinalysis. Treatments include watchful waiting, medication and surgery. In

Beta Blocker

Clinical Definition Patients with heart disease often take beta blockers, a class of heart medication that treats heart failure, high blood pressure and tachycardia (abnormally fast heart rate). After a time, a beta blocker may enhance the pumping ability of your heart and improve mortality even in those with severe cardiovascular disease and heart failure.

Bile Acid

Clinical Definition In the body, bile acids are fatty substances formed from cholesterol and secreted by the liver to help the body digest fats and fatty acids. In Our Own Words Bile acids are weak acids, formed in the body from cholesterol. Bile ducts carry bile from the liver to the gallbladder and then, when

Bipolar Disorder

Clinical Definition Bipolar disorder is a mental disorder characterized by pathological mood swings from mania to depression. There is no clear cause for the disorder, although there appears to be a genetic link, and scientists are trying to understand differences in brain development, connections and activity in affected individuals. The disorder is often treated with

Bird Flu

Clinical Definition Avian flu, or bird flu, is an infectious disease caused by avian flu (bird influenza A) viruses. Many different strains of the virus exist in the intestines of migrating wild birds, and some of these strains can cause mild to serious symptoms. These viruses typically infect only other fowl, but on rare occasions,

Blood Poisoning

Clinical Definition Blood poisoning, known medically as septicemia, is a condition that occurs when disease-causing organisms are living in the bloodstream, often having travelled from an infection elsewhere in the body, such as the lungs, abdomen or urinary tract. Chills and high fever are often early symptoms. Blood poisoning is serious and potentially life-threatening and

Blood Pressure

Clinical Definition Blood pressure is the force or tension applied to arterial walls of the heart during systematic circulation. Blood pressure measurement includes systolic pressure, which occurs during contractions of the myocardium, and diastolic pressure, which occurs when the heart is between beats. A normal adult blood pressure reading is: Systolic less than 120mmHg and

Bone Scan

Clinical Definition A bone scan is a nuclear imaging test that shows skeleton metabolism and cell activity. During the procedure, a radionuclide is injected into a vein. Gamma radiation is omitted from the radionuclide and collects in areas of the bone tissue where there are abnormalities. The areas where the radiation has collected are detected

Bone Spur

Clinical Definition Bone spurs, or osteophytes, are outgrowths of bone that are typically found on the bones of joints, such as the ankle or vertebrae. Bone spurs can be indicative of a condition such as arthritis, and may also contribute to painful symptoms on their own.Bone spurs, or osteophytes, are outgrowths of bone that are

Borderline Personality Disorder

Clinical Definition Borderline personality disorder, or BPD, is considered a serious mental illness. It’s one of a group of conditions under the umbrella term of personality disorders. Those with BPD have often intense, unstable emotions and engage in risky behaviors such as overspending, unsafe sex or abusing drugs and alcohol. In Our Own Words Borderline

Brachial Neuritis

Clinical Definition Brachial neuritis is a type of neuropathy in which inflammation of the brachial plexus develops. The etiology of the inflammation is often unknown. In addition to inflammation, a sudden onset of pain and weakness in the shoulders and hands occurs. Although the condition may occur bilaterally, it is more frequently unilateral. In Our

Brain Tumor

Clinical Definition A neoplasm in the intracranial region of the central nervous system is referred to as a brain tumor. It can develop due to a mutation in cell DNA that leads to abnormal cell growth and mass formation. Brain tumors can be either benign or malignant and are also considered either primary or secondary.

Breakthrough Pain

Clinical Definition Breakthrough pain is a flare of pain that occurs in cancer patients even if they are taking pain reliever medication on a regular schedule as part of their cancer treatment. The term originates because it ”breaks through” the pain relief expected from the scheduled pain medicine. Breakthrough pain is very unpredictable, typically comes


Clinical Definition Bronchitis is inflammation of the main bronchial tubes leading to the lungs. In some instances, there may also be tracheal involvement. The condition can develop acutely from infectious agents like the parainfluenza virus, or occur chronically from bronchial epithelial injury due to lung irritants like cigarette smoking. In Our Own Words Bronchitis, when


Clinical Definition A bronchodilator is any drug, medicine or substance that causes the bronchial tubes of the respiratory tract to dilate, relaxing the bronchial muscles and increasing oxygenated airflow to the lungs. In Our Own Words Bronchodilators are most commonly referred to as types of medications that help relax and widen (or “dilate”) the air


Clinical Definition Bruxism is considered a type of movement disorder, which involves the unintentional act of clenching the jaw or vigorously grinding your teeth, usually during sleep. In Our Own Words Bruxism is the medical term for grinding your teeth during sleep or unconsciously during stressful situations. Grinding involves sliding the teeth back and forth

Bulimia Nervosa

Clinical Definition Bulimia nervosa is an eating disorder characterized by episodes of excessive overeating, followed by a variety of compensatory actions to avoid weight gain, including vomitting, laxatives, fasting or immoderate exercise. In Our Own Words Bulima nervosa sufferers fear gaining weight and are very unhappy with their body image. They are often perfectionists with


Clinical Definition Bursitis is pain and swelling of the bursae, the small fluid-filled pads in or near the joints. Bursae help cushion any tissues that rub against or slide over hard bone. Pain and swelling are common symptoms of bursitis, and a person can have trouble moving his or her joints. Often caused by repetitive


Clinical Definition The original definition of a calorie was the quantity of heat needed to raise the temperature of 1 kilogram of water from 0 to 1 degree Celsius. Now, it is commonly used as a unit for measuring the amount of energy contained in food. In Our Own Words A calorie is the unit


Clinical Definition Cancer is not a single disease, but the general name that applies to more than 100 diseases. Each cancer has in common abnormal cells that grow in an uninhibited way and in the process, possibly forming tumors (i.e., abnormal growth of tissue). Cells become cancerous due to deoxyribonucleic acid (DNA) damage. In every

Canker Sore

Clinical Definition Canker sores, also known as aphthous ulcers, are painful oral sores that are typically red in color but sometimes with a white, yellow or gray center. Traditionally less than a millimeter in diameter, they appear on the inside of the lips, inside the cheeks, under the tongue or at the base of the


Clinical Definition This macronutrient is an organic compound that is made up of carbon, hydrogen and oxygen molecules. The structure of the molecules dictates whether it is a monosaccharide (glucose, galactose and fructose), disaccharide (sucrose, lactose and maltose) or polysaccharide (starch and glycogen). In Our Own Words Carbohydrates are nutrients the body needs in relatively


Clinical Definition A carcinogen is an agent or substance that may damage cellular DNA or alter cell metabolism, and, in so doing, potentially lead to the development of cancer. Carcinogens are classified according to their carcinogenicity. In Our Own Words A carcinogen is something believed to contribute to the development of cancer. Usually, a carcinogen

Caregiver Stress

Clinical Definition Caregiver’s stress is a state of exhaustion – physical, mental and emotional – that occurs when those who attend to others with chronic medical conditions do not get the help they need, or stretch themselves too thin physically or financially. When anxiety progresses to a feeling of recurring burnout, research shows that caregivers’

Carpal Tunnel Syndrome

Clinical Definition Carpal tunnel syndrome is a compression neuropathy that occurs when increased pressure of the median nerve in the proximal forearm develops. The median nerve, which extends from the forearm to the hand, provides motor and sensory function to the thumb and three of the fingers. When compression occurs, hand function can be compromised.


Clinical Definition Cataplexy is an acute, transient attack characterized by hypertonia and weakness. Weakness can be generalized or limited to certain muscle groups. Precipitating factors associated with cataplexy are intense emotional stimuli, such as anger and fear. A decrease in hypocretin, which is a neurotransmitter, is believed to be a contributing factor to cataplexy. Cataplexy


Clinical Definition Normally, the lens in the eyes are clear or transparent. However, a cataract is an abnormal clouding or opacity of the eye’s crystalline lens. The opacity can lead to a decrease in vision and possibly blindness. Cataracts are thought to develop as a result of age-related degenerative alterations to the proteins in the


Clinical Definition A cavity is the progressive demineralization of the structure of the tooth, causing a hollow space. Acid from dental plaque damages the tooth and leads to destruction of the tissue. A cavity starts by invading the enamel, but can progress into deeper structures including the dentin and cementum. In Our Own Words A cavity

Celiac Disease

Clinical Definition Celiac disease is a digestive, autoimmune disorder characterized by intolerance to gluten, a protein found in wheat products and other foods. When gluten is ingested, the immune system forms antibodies that bind to parts of the villi of the small intestine, resulting in inflammation, damage to the intestine and malnutrition. In Our Own

Cervical Cancer

Clinical Definition Cervical cancer originates in the uterine cervix, and is primarily either squamous cell carcinoma or adenocarcinoma. The majority are squamous cell carcinomas, although some have characteristics of both types and are known as mixed carcinoma. Early symptoms are atypical. Risk factors include lack of screening with a Pap smear, infection with human papillomavirus

Chagas Disease

Clinical Definition Chagas disease is an infection transmitted by insects, caused by the parasite Trypanosoma cruzi and common in South and Central America. In acute phases, symptoms may be non-existent or mild, such as fever and malaise. In the chronic phase, which may take 20 years to develop, arrhythmias, tachycardia and enlarged lymph nodes may occur. In

Chemo Brain

Clinical Definition Chemo brain is the mild cognitive impairment experienced by some cancer patients pre-treatment, during and post-treatment. Characteristics include memory lapses, concentration difficulties and difficulty multi-tasking.  Some researchers have found alterations in brain activity patterns on electroencephalograms (EEGs) in those on chemotherapy. Coping focuses on organizational techniques, sleep hygiene and exercise, as well as


Clinical Definition Chemotherapy refers to chemicals used to treat cancer, and commonly involves use of antineoplastic drugs used to treat neoplastic disease. The drugs have a cytotoxic effect on cancer cells. Chemotherapy is often used as a systematic treatment for various forms of malignant neoplasms. In Our Own Words Chemotherapy is a form of cancer


Clinical Definition Cholesterol is a fat-like substance produced by the liver; it is also an animal sterol found in all foods from animal products. While it is an essential cellular component, cholesterol can cause atherosclerosis (i.e., arterial plaque buildup) when too much exists in the blood stream, leading to heart disease and stroke. In Our

Chronic Cough

Clinical Definition Chronic cough, or persistent cough, is a cough that persists more than eight weeks. Not a disease itself, it originates from other health conditions, typically related to asthma, smoking, gastroesophageal reflux disease (GERD), sinusitis and other problems. Treatment depends on the etiology. In Our Own Words Chronic cough is one that lasts a

Chronic Obstructive Pulmonary Disease

Clinical Definition COPD, or chronic obstructive pulmonary disease, is a term used to refer to a group of diseases, including emphysema and chronic bronchitis. All these diseases involve airflow obstruction and breathing-related problems. The typical course of COPD is gradual progression, with airflow lung function worsening. Because COPD adds to the work of the heart,


Clinical Definition Claustrophobia is a persistent, irrational fear of enclosed spaces. The phobia, a type of anxiety disorder, triggers reactions and anxiety symptoms such as dizziness, nausea and tachycardia, which results in avoidance of situations or objects that trigger it. Desensitization, medication and cognitive therapy can help. In Our Own Words Claustrophobia is fear of

Cluster Headache

Clinical Definition Cluster headaches appear to be associated with activity in the hypothalamus, the brain region that houses the circadian clock and the trigeminal nerve. Though not nearly as common as tension headaches or migraines, cluster headache pain can last anywhere from 15 minutes to three hours or so. The trigeminal nerve triggers the ocular


Clinical Definition Colitis is a medical condition that exhibits inflammation of the colon, whether caused by an inflammatory bowel disease, infection, or some other process. In Our Own Words Colitis is characterized by inflammation of the colon. There are many different kinds of colitis, including infectious colitis, ulcerative colitis, diverticular colitis, and radiation colitis. In

Common Cold

Clinical Definition The common cold is a viral infection of the upper respiratory tract, usually involving a sore throat, runny nose, sneezing and coughing. Symptoms often last for up to two weeks. In Our Own Words More than 200 different viruses are known to cause the common cold, but most often, it’s a rhinovirus. When


Clinical Definition A concussion is a type of traumatic brain injury or TBI that can alter the usual and normal functioning of the brain. Concussions are caused by a jolt, blow or bump to the head, often during sports, and this can trigger headaches, dizziness and neck pain. Concussions are considered mild brain injuries, but


Clinical Definition Congestion is an excessive accumulation of bodily fluids, such as mucus or blood, in an organ, vessel or body part. It may develop in a part of the body due to obstruction in normal fluid movement or an increased influx of fluid. The term most commonly refers to nasal congestion, but can also

Congestive Heart Failure

Clinical Definition Congestive heart failure refers to a decrease in the heart’s ability to pump blood, which in turn is associated with congestion and edema in the tissues, potentially including the lungs. Heart failure may be associated with symptoms such as shortness of breath, edema, vein distension in the neck’s (jugular) veins or an enlarged


Clinical Definition Contamination is the presence of an unwanted or harmful agent, such as bacteria. Contamination may involve the body or inanimate objects (e.g., surgical instruments, bandages or dressings). Food and liquids can also become contaminated. In some instances, contamination may lead to an infection or illness. In Our Own Words Contamination is the introduction


Clinical Definition Coronavirus is a genus in the family Coronaviridae. It is a causative agent of upper respiratory tract infections, which may range from the common cold to severe acute respiratory syndrome (SARS). Less commonly, coronavirus may also cause gastroenteritis, pancreatitis and infectious peritonitis. It may be transmitted through inhalation of respiratory droplets from an


Clinical Definition Corticosteroids are synthetic compounds that produce physiological effects similar to the chemicals produced by the human adrenal cortex. Corticosteroids decrease the inflammatory process and the immune system response, which may have a therapeutic effect on a variety of diseases. In Our Own Words Corticosteroids are a type of medication made to induce some

CPAP Machine

Clinical Definition A CPAP machine is a medical device that delivers continuous positive airway pressure to the airways. It prevents alveoli collapse during exhalation and increases functional residual capacity in the lungs. In Our Own Words CPAP stands for continuous positive airway pressure, and a CPAP machine can treat certain types of breathing disorders. It

Creutzfeldt-Jakob Disease

Clinical Definition Creutzfeldt-Jakob disease is a rare neurodegenerative disease that occurs due to prion proteins, which are even smaller than viruses. The disease is classified as a spongiform encephalopathy due to the formation of vacuoles in the gray matter of the brain. The condition causes rapid deterioration of brain function and is fatal. There are

Crohn’s Disease

Clinical Definition Crohn’s disease is a chronic, inflammatory disease of the gastrointestinal tract most often in the ileum and large intestine. Inflammation can lead to abscesses and ulcers, and chronic symptoms may result in fibrosis, stenosis and bowel obstruction. In Our Own Words Crohn’s disease is an inflammatory gastrointestinal disease of unknown cause that affects


Clinical Definition A decongestant is a medication that causes vasoconstriction of the blood vessels lining the nasal cavity or sinuses. This action may reduce tissue swelling and decrease congestion in the nose. Due to their vasoconstriction action, decongestants may cause hypertension as a side effect. In Our Own Words Decongestants are used to treat nasal

Deep Venous Thrombosis

Clinical Definition A deep venous thrombosis refers to a stationary blood clot, or thrombus formation, inside a vein. It usually develops in proximal veins of the lower extremities, and elements believed to contribute to thrombus formation include vascular injury, blood stasis and hypercoagulability. A pulmonary embolism is a serious complication of deep venous thrombosis. In


Clinical Definition A defibrillator is a medical device that can administer a therapeutic, electrical impulse to the myocardium of the heart. It is used to eradicate life-threatening arrhythmias and re-establish a normal contraction rhythm of the heart. In Our Own Words A defibrillator is a device used to deliver an electrical shock to the heart

Degenerative Disc Disease

Clinical Definition Degenerative disc disease is the deterioration of one or more of the intervertebral discs in a person’s spine. The condition reduces the disc’s ability to handle mechanical stress, such as twisting and bending, leading to back pain.  Aging, drying out and wear of a disc, which reduces the disc’s ability to absorb shock,


Clinical Definition Dehydration is a lack of adequate water in the body that can be hazardous and even life-threatening, often occurring due to inadequate fluid intake during hot weather, exercise, fever, diarrhea or vomiting. Older adults and those on diuretic medications for hypertension are also prone to dehydration.  Symptoms may include dry mouth, dry cough,


Clinical Definition Dementia is not a specific disease but a descriptive term for a collection of symptoms severe enough to interfere with daily life, such as a decline in memory, judgment or other thinking skills. These symptoms occur in many different disorders. Dementia is not a normal part of aging but is common in very


Clinical Definition Depression is characterized by a dejected mood and a cluster of other symptoms that persist throughout the majority of each day, in a time span of 2 weeks or more. These symptoms include five or more of the following tendencies: sleep changes, eating and appetite changes, low energy, poor concentration, agitation, slowness, thoughts


Clinical Definition Dermatitis is an umbrella term that describes an epidermal inflammation that can manifest as a range of skin irritations and rashes, ranging from mild to severe. In Our Own Words There are several common types of dermatitis (i.e., an irritation of the skin that can manifest in redness, irritation, itchiness and rashes), including


Clinical Definition Diarrhea is the frequent discharge of loose bowel movements consisting of semisolid or fluid fecal matter. Diarrhea has many potential causes and may be acute or chronic. In Our Own Words Diarrhea, sometimes called ”the runs,” is a watery, loose stool that can be a nuisance due to frequent trips to the toilet.


Clinical Definition A disinfectant is an agent used to destroy or inhibit the growth of pathogenic microorganisms. Most commonly, disinfectants are chemical substances used to prevent the spread of disease causing organisms. The disinfectant is typically applied to an inanimate object, such as a surgical tool. It differs from an antiseptic, which is applied to


Clinical Definition Diverticulitis is a condition that results when one or more diverticula become inflamed and infected. When the pouches become blocked with waste materials and bacterial buildup, the site then becomes inflamed and infected.  Cramps, abdominal tenderness, chills and fever can occur as the infection progresses. While the condition may resolve on its own,

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