Medicine

2019 Measles Outbreak in Samoa 2019 Samoa measles outbreak A severe measles outbreak in Samoa began in September 2019, producing thousands of cases and dozens of deaths and prompting a national state of emergency and mass vaccination campa…

Abdominal migraine Abdominal migraine is a recurrent disorder, mostly in children, causing episodes of intense midline abdominal pain with nausea, pallor and other migraine‑like features; diagnosis i…

Abdominal obesity (central obesity) Abdominal obesity Abdominal obesity is excess fat around the abdomen. This article explains what it is, how it is measured, health implications, causes, prevention and how it differs from other patt…

Abdominal pain: causes, symptoms, diagnosis and when to seek care Abdominal pain Abdominal pain—commonly called a stomach ache—is discomfort in the belly with many causes. This article explains typical patterns, common causes, diagnostic approaches, basic treat…

Abortion: definitions, types, methods, legal context and health considerations Abortion Abortion is the medical termination of a pregnancy. This article explains terminology, types (spontaneous vs induced), common methods, health and legal issues, and distinctions suc…

Abrasion (medical) A superficial skin injury that scrapes or rubs away the epidermis. Often called a scrape or graze, it usually heals without scarring but can bleed, become infected, or scar if deep…

Abscess (medical condition): causes, symptoms, diagnosis, and treatment Abscess An abscess is a localized collection of pus that forms within body tissues, most often from infection. Overview of appearance, causes, assessment, management, risks and prevention.

Abstinence: Voluntary restraint from pleasurable activities Abstinence Abstinence is the deliberate avoidance of pleasurable bodily activities—commonly sex, alcohol, or food—practiced for personal, medical, moral, or religious reasons and distinct fro…

Acephalgic migraine (silent migraine): overview, features, and care Acephalgic migraine Acephalgic migraine, or silent migraine, causes typical migraine aura without headache. It is diagnosed by symptom pattern and distinguished from stroke or epilepsy; treatment and…

Achlorhydria — absence of stomach acid: causes, effects, diagnosis, management Achlorhydria Achlorhydria is the complete lack of gastric acid. This article explains causes, symptoms, diagnostic approaches, complications, and common management strategies in clear, concise…

Acne: causes, types, treatment, and prevention Acne Overview of acne (acne vulgaris): causes, lesion types, typical locations, diagnosis, evidence-based treatments, prevention strategies and when to seek medical care.

Acromegaly — causes, symptoms, diagnosis, and treatment Acromegaly Acromegaly is a rare hormonal disorder caused by excess growth hormone after puberty, producing characteristic tissue overgrowth, metabolic effects, and increased health risks if u…

Acupuncture: practice, history, uses, and safety Acupuncture A concise encyclopedia entry on acupuncture: its principles, techniques, historical roots, evidence for use, common applications, safety concerns, and regulatory context.

Acute An adjective meaning sharp or sudden; used in medicine (rapid onset), geometry (angles under 90°), and writing (acute accent). Explains senses, examples, history, and key distincti…

Acute (medicine) Overview of acute medical conditions: definition, features, distinction from subacute and chronic, typical settings and examples, and why the term does not always mean severe.

Acute myeloid leukemia: overview, diagnosis, treatment, and key facts Acute myeloid leukemia Acute myeloid leukemia (AML) is a rapid cancer of myeloid blood cells that disrupts bone marrow function. This article explains causes, signs, diagnosis, classification, therapies,…

Acute radiation syndrome (radiation sickness) Acute radiation syndrome Acute radiation syndrome is an illness caused by short-term, high-dose exposure to ionizing radiation that damages rapidly dividing tissues; severity and outcome depend on dose and…

Adam's apple (laryngeal prominence) Adam's apple The Adam's apple is the visible laryngeal prominence formed by the thyroid cartilage. It varies by sex and age, influences voice pitch, and has medical and cultural significance.

Addenbrooke's Hospital — Cambridge teaching hospital and research centre Addenbrooke's Hospital Addenbrooke's Hospital is a major teaching and tertiary referral hospital in Cambridge, England, known for clinical care, research and education within the Cambridge Biomedical Cam…

Adderall (amphetamine mixed salts): uses, formulation, effects, and risks Adderall Adderall is a brand of mixed amphetamine salts used to treat ADHD and narcolepsy. This article explains its composition, how it works, formulations, therapeutic uses, side effects,…

Addison's disease: primary adrenal insufficiency and management Addison's disease Addison's disease is chronic adrenal insufficiency, usually from autoimmune damage, causing fatigue, weight loss, low blood pressure and skin darkening; treated with steroid replac…

Adduction (movement toward the body's midline) Adduction Adduction is the movement of a body part toward the midsagittal (median) plane or limb axis. It is produced by adductor muscles, contrasted with abduction, and important for postur…

Adenoidectomy: surgical removal of the adenoids Adenoidectomy Adenoidectomy is the surgical removal of adenoid tissue, mainly in children, to relieve nasal obstruction, recurrent ear infections, or sleep-disordered breathing. Procedure, recov…

Adrenal tumor (adrenal mass): overview, types, diagnosis and management Adrenal tumor Adrenal tumors are growths in the adrenal glands that may be benign or malignant and can alter hormone production. This article explains types, symptoms, diagnosis, treatment and i…

Adrenoleukodystrophy (ALD): causes, symptoms, diagnosis and care Adrenoleukodystrophy Adrenoleukodystrophy (ALD) is an X-linked disorder causing accumulation of very long‑chain fatty acids, progressive demyelination and adrenal failure. It mainly affects males; earl…

Adverse effect (medicine): causes, classification and management Adverse effect (medicine) An adverse effect is an unintended harmful response to a medical intervention. This article explains what adverse effects are, how they arise, how they are classified, detected, re…

Agoraphobia: overview, symptoms, causes, diagnosis and treatment Agoraphobia Agoraphobia is an anxiety disorder characterized by fear of situations perceived as hard to escape or where help may be unavailable. It can limit mobility and daily functioning but…

Agranulocytosis: causes, symptoms, diagnosis and treatment Agranulocytosis Agranulocytosis is a life‑threatening drop in granulocytes (especially neutrophils) leading to severe infection risk. This article explains causes, signs, diagnosis, management and…

Acquired Immunodeficiency Syndrome (AIDS) AIDS AIDS is the late, life‑threatening stage of infection caused by HIV, marked by severe immune deficiency, opportunistic infections, and the need for lifelong antiretroviral therapy…

Albuterol (salbutamol): short-acting bronchodilator Albuterol Albuterol, also called salbutamol, is a short-acting beta2-adrenergic bronchodilator used to relieve bronchospasm in asthma and COPD. Delivered by inhaler, nebulizer, or oral formu…

Alcohol tolerance: mechanisms, types, and clinical implications Alcohol tolerance Overview of how repeated alcohol exposure changes physiological and behavioral responses, types and causes of tolerance, health risks including withdrawal, and implications for tre…

Alcohol withdrawal: causes, symptoms, timeline, and treatment Alcohol withdrawal Alcohol withdrawal is a potentially serious cluster of symptoms following reduced or stopped drinking in dependent individuals. This article explains signs, risks, management, and…

Alcoholism (Alcohol Use Disorder): Causes, Symptoms, and Treatment Alcoholism Alcoholism, or alcohol use disorder, is a chronic condition marked by impaired control over drinking, health and social harms, and potential dependence; it is treatable through the…

Allergic rhinitis (hay fever): causes, symptoms and treatment Allergic rhinitis Allergic rhinitis (hay fever) is inflammation of the nasal lining caused by airborne allergens. This article explains symptoms, common triggers, mechanisms, diagnosis, treatments a…

Allergy: causes, symptoms, diagnosis, and management Allergy An allergy is an immune system hypersensitivity to normally harmless substances. This article explains mechanisms, common triggers, symptoms, diagnosis, treatments and differences…

Alprazolam: uses, effects, risks and clinical overview Alprazolam Alprazolam (Xanax) is a short-acting benzodiazepine used for anxiety and panic disorder. This article explains its action, uses, side effects, dependence risks, interactions, and c…

Alternative medicine Practices and systems used instead of or alongside conventional medicine, encompassing traditional, spiritual, and non–evidence-based therapies; varies widely in methods, history,…

Alzheimer's disease: overview, causes, symptoms, treatment, and history Alzheimer's disease Comprehensive overview of Alzheimer's disease: its pathology, symptoms, diagnosis, treatment options, risk factors, prevention strategies, epidemiology, caregiving and historical b…

Ambroise-Paré Hospital, Boulogne-Billancourt Ambroise-Paré Hospital Public teaching hospital in Boulogne-Billancourt near Paris, founded in 1923; major regional medical center with clinical departments, teaching links to Université de Versailles Sa…

Amniocentesis: prenatal diagnostic procedure Amniocentesis Invasive prenatal diagnostic test sampling amniotic fluid to analyze fetal cells and chemicals for chromosomal, genetic and some neural-tube defects; offered when risk is increased…

Amoebiasis (Amebiasis): intestinal infection caused by Entamoeba Amoebiasis Amoebiasis is an intestinal infection typically caused by Entamoeba histolytica. It ranges from silent carriage to severe colitis or liver abscess. Transmission is fecal–oral; prev…

Amphetamine: overview, effects, medical uses, history and risks Amphetamine Amphetamine is a synthetic stimulant used medically (ADHD, narcolepsy) and misused recreationally. This article explains its action, forms, history, uses, risks and legal context.

Amputation: causes, procedure, rehabilitation and history Amputation Amputation is the surgical removal or traumatic loss of a limb or part of the body. This article explains causes, types, procedure, rehabilitation, prosthetics and historical or le…

Amyloidosis: causes, types, diagnosis, and clinical significance Amyloidosis Amyloidosis is a group of disorders caused by abnormal protein fibril deposits in tissues. This article explains types, pathology, symptoms, diagnosis, treatment approaches and not…

Anal cancer: overview, causes, diagnosis and treatment Anal cancer Anal cancer is an uncommon malignancy arising in the anus, most often squamous cell carcinoma linked to HPV. This article covers causes, symptoms, diagnosis, staging, treatment and…

Anal fissure: causes, symptoms, diagnosis, treatment and prevention Anal fissure An anal fissure is a small tear in the lining of the anal canal that causes sharp pain and sometimes bleeding. This article explains causes, signs, evaluation, treatment options an…

Analgesic (painkiller): overview, types, uses and risks Analgesic Analgesics, or painkillers, are drugs that reduce pain by acting on the nervous system. This article outlines types, how they work, common uses, risks and historical notes.

Anaphrodisiac: substances and measures that reduce sexual desire Anaphrodisiac An anaphrodisiac is an agent—drug, food, herb, or procedure—that reduces sexual desire or activity. Used in medicine, animal husbandry, and historical practice, they contrast with…