Medicine
Health, disease and medical science
Articles in this category are re-verified roughly every 60 days.
Medicine
1918 Influenza Pandemic
The 1918 influenza pandemic, also known as the Spanish flu, was a global outbreak of influenza A(H1N1) that spread in 1918–1919. The pandemic infected a large share of the world's population and caused tens of millions of deaths; its precise origin and total death toll remain uncertain.
Updated 1 Nov 2026
Medicine
Alzheimer's disease
Alzheimer's disease is a progressive brain disorder and the most common cause of dementia. It gradually impairs memory and other thinking abilities, eventually affecting everyday activities. Characteristic brain changes include amyloid plaques, tau tangles and loss of neurons and their connections, although the causes are not fully understood and vary in importance among people. Age is a major risk factor, but the disease is not an inevitable part of ageing. Diagnosis combines clinical assessment with tests that help distinguish Alzheimer's from other causes of cognitive change; available treatments can ease some symptoms or slow decline for selected patients, but do not cure the disease.
Updated 15 Oct 2026
Medicine
Anesthesia
Anesthesia is the use of medicines and techniques to prevent or reduce pain during medical procedures. Local and regional methods block sensation in selected areas; general anesthesia causes unconsciousness, while sedation can reduce awareness without necessarily doing so. The approach is chosen for the procedure and patient, and is paired with monitoring because anesthetic effects and risks vary.
Updated 17 Oct 2026
Medicine
Antibiotics
Antibiotics are medicines used to kill bacteria or inhibit their growth, making them essential for treating many bacterial infections. Different antibiotics act on different bacterial processes, and they do not treat viral illnesses such as colds or influenza. Their transformative medical value is challenged by antibiotic resistance, which develops in bacteria and can spread when resistant microbes survive and multiply.
Updated 12 Oct 2026
Medicine
Antimicrobial resistance
Antimicrobial resistance (AMR) occurs when microorganisms such as bacteria, viruses, fungi and parasites no longer respond to medicines used against them. It can make infections harder to treat and threaten routine health care. Resistance can arise naturally, but inappropriate antimicrobial use and weak infection prevention can favor resistant organisms and their spread. Because it links human, animal, plant and environmental health, AMR is addressed through coordinated surveillance, prevention and responsible use of medicines.
Updated 16 Oct 2026
Medicine
Asthma
Asthma is a chronic lung disease in which inflammation and narrowing of the airways cause respiratory symptoms that vary over time. Common symptoms include wheezing, cough, breathlessness and chest tightness; flare-ups can be triggered by factors such as viral infections, exercise, allergens or air pollution. Diagnosis combines a history of variable symptoms with tests of lung function, and treatment can control symptoms and reduce attacks, though asthma has no single cure.
Updated 13 Oct 2026
Medicine
Blood transfusion
A blood transfusion gives a person whole blood or selected blood components, usually through an intravenous line. It can replace blood lost through injury or surgery and support treatment when a person cannot produce enough of a needed blood component. Compatibility testing and donor screening reduce risks, but reactions and unequal access to safe blood remain important concerns.
Updated 17 Oct 2026
Medicine
Botulism
Botulism is a rare, serious illness caused by botulinum neurotoxin, which disrupts nerve function and can lead to progressive muscle weakness, paralysis and respiratory failure. It can follow ingestion of toxin-contaminated food, toxin production in wounds or the intestines, or, rarely, medical exposure or inhalation. Because early antitoxin treatment can limit further harm, suspected botulism is treated as a medical emergency; it does not spread from person to person.
Updated 20 Oct 2026
Medicine
Cancer
Cancer is a broad group of diseases in which abnormal cells grow without normal controls and may invade nearby tissues or spread to distant parts of the body. Different cancers arise in different cell types and are shaped by distinct genetic changes, exposures and other risk factors. Diagnosis and treatment depend on the particular cancer and its extent; prevention, early diagnosis, evidence-based screening and access to effective care can reduce illness and deaths.
Updated 15 Oct 2026
Medicine
Chagas disease
Chagas disease, also called American trypanosomiasis, is an infection caused by the parasite Trypanosoma cruzi. In endemic parts of the Americas it is commonly transmitted when infected triatomine insects' feces enter the body through a bite wound, broken skin or a mucous membrane; congenital, food-borne, transfusion and transplant transmission also occur. Infection can remain unnoticed for years, but may later damage the heart or digestive system. Early diagnosis, antiparasitic treatment and targeted prevention help reduce its effects and spread.
Updated 19 Oct 2026
Medicine
Cirrhosis
Cirrhosis is advanced, lasting scarring of the liver: scar tissue replaces healthy tissue, impairs normal function and partly obstructs blood flow through the organ. It usually follows long-term liver injury, may cause no early symptoms, and can lead to complications including portal hypertension, fluid accumulation, bleeding and liver failure.
Updated 19 Oct 2026
Medicine
Clinical trials
Clinical trials are interventional studies in which researchers assign participants to one or more interventions to learn about effects on health. A protocol sets out the research question, eligibility rules, procedures and outcomes; some trials use random assignment or comparison groups, but not all do. Drug-development programs often use phases to organize questions about safety and benefit. Independent ethical review, voluntary informed consent, public registration and responsible reporting help protect participants and make findings assessable.
Updated 17 Oct 2026
Medicine
Cochlear implant
A cochlear implant is an electronic medical device that can provide a sense of sound for some people with severe or profound hearing loss. Unlike a hearing aid, it bypasses damaged parts of the inner ear and electrically stimulates the auditory nerve. Its external sound processor works with surgically implanted components, and users typically need rehabilitation to learn to interpret the signals. It does not restore normal hearing, and outcomes vary.
Updated 6 Nov 2026
Medicine
Cognitive behavioral therapy
Cognitive behavioral therapy (CBT) is a family of psychotherapies that examines how thoughts, emotions and actions interact. In structured work with a therapist, a person learns to identify unhelpful patterns, test alternative responses and practise coping skills. CBT is used for several mental-health and other problems, in individual, group and self-help formats. Its methods and evidence vary by condition; research supports its use in some settings but does not make it a universal remedy or establish that it is always superior to other therapies.
Updated 17 Oct 2026
Medicine
Cystic fibrosis
Cystic fibrosis (CF) is an inherited disorder caused by disease-causing variants in both copies of the CFTR gene. The resulting disruption of salt and water movement makes mucus unusually thick, especially affecting the lungs and digestive system. Screening, continuing specialist care and treatments that target particular CFTR variants have changed the outlook for many people with CF.
Updated 21 Oct 2026
Medicine
Dengue
Dengue is a viral infection transmitted mainly by infected Aedes mosquitoes, particularly Aedes aegypti and Aedes albopictus. It is widespread in tropical and subtropical regions; the World Health Organization estimates that about half of the world's population is at risk. Many infections cause no symptoms or mild illness, while severe dengue can involve plasma leakage, shock, serious bleeding or organ impairment. Infection with one of the four widely recognized dengue virus serotypes gives lasting immunity to that serotype but only limited protection against the others; a second infection carries a greater risk of severe disease. Prevention relies chiefly on mosquito control, and clinical care is supportive because no specific antiviral treatment is available.
Updated 19 Oct 2026
Medicine
Diabetes mellitus
Diabetes mellitus is a group of chronic metabolic conditions in which blood glucose remains too high because the body does not make enough insulin or cannot use it effectively. Its main forms are type 1, type 2 and gestational diabetes, which differ in their causes and management. Without adequate management, high blood glucose can damage blood vessels, nerves, eyes, kidneys and other organs; treatment and prevention strategies depend on the type.
Updated 13 Oct 2026
Medicine
Ebola virus disease
Ebola virus disease (EVD) is a severe infection caused by Ebola virus, currently classified as the species Orthoebolavirus zairense. The term is distinct from the broader “Ebola disease,” which public-health agencies also use for related illnesses caused by other orthoebolaviruses.
Updated 20 Oct 2026
Medicine
Endometriosis
Endometriosis is a chronic condition in which tissue resembling the lining of the uterus grows elsewhere in the body, most often in the pelvis. The condition can cause inflammation, scar tissue, pelvic pain, painful or heavy periods, bowel or urinary symptoms, and difficulty becoming pregnant, although symptoms vary and some people have none. Its causes are not fully understood, diagnosis may be delayed, and there is no known cure; care aims to manage symptoms and their effects.
Updated 16 Oct 2026
Medicine
Epidemiology
Epidemiology studies how health-related conditions and events are distributed across populations, what factors shape their occurrence, and how that knowledge can guide prevention and control. It combines measurement, surveillance, descriptive observation and analytic comparison. Measures such as incidence and prevalence answer different questions about new and existing cases, while sound interpretation depends on population, time period, study design and possible sources of bias.
Updated 15 Oct 2026
Medicine
Epilepsy
Epilepsy is a group of brain disorders marked by an enduring tendency to produce epileptic seizures—temporary episodes of abnormal electrical activity that can affect movement, sensation, awareness, or behavior. A single seizure does not automatically mean a person has epilepsy: clinical criteria also consider recurrence risk and epilepsy syndromes. Causes, seizure types, and effects vary, and treatment is individualized; many people achieve good seizure control.
Updated 18 Oct 2026
Medicine
Hippocratic Oath
The Hippocratic Oath is an ancient Greek medical text that sets out duties for physicians and their students. Traditionally associated with Hippocrates, it is usually dated to around the fourth century BCE, but its precise authorship and date are uncertain. Its themes include patient benefit, professional conduct, confidentiality and teaching; the text and its later adaptations differ from modern medical pledges.
Updated 15 Oct 2026
Medicine
Hypertension
Hypertension, or high blood pressure, is a sustained elevation of pressure in the arteries. Blood pressure has systolic and diastolic components, and diagnostic thresholds differ among clinical guidelines. Often it has no noticeable symptoms, but over time it can damage the heart, brain, kidneys and other organs. Population-level prevention, repeated measurement and appropriate medical treatment are central to reducing its effects.
Updated 16 Oct 2026
Medicine
Insulin
Insulin is a peptide hormone produced chiefly by pancreatic beta cells in the islets of Langerhans. It helps maintain glucose balance by promoting glucose uptake in muscle and fat, encouraging storage of glucose as glycogen, and reducing the liver's release of glucose. As a medicine, insulin replaces or supplements the body's hormone when needed. Its isolation for treatment in the early 1920s transformed diabetes care; recombinant methods later enabled large-scale production of human insulin.
Updated 18 Oct 2026
Medicine
Malaria
Malaria is a potentially life-threatening parasitic disease, usually transmitted to people by infected female Anopheles mosquitoes. Its parasites pass through stages in the human liver and blood and complete part of their life cycle in mosquitoes. The disease is concentrated in tropical regions, but early diagnosis, effective treatment, mosquito control, preventive medicines and vaccines can reduce illness and deaths.
Updated 13 Oct 2026
Medicine
Malnutrition
Malnutrition is a broad term for deficiencies, excesses or imbalances in a person's intake or use of energy and nutrients. It includes undernutrition, micronutrient-related problems, and overweight, obesity and some diet-related diseases. Its causes and effects are shaped by diets, illness, care, food access and wider living conditions, so it is not simply another word for hunger.
Updated 14 Oct 2026
Medicine
Measles
Measles is a highly contagious viral disease that usually begins with fever and respiratory symptoms, followed by a distinctive rash. It can cause serious complications, particularly in young children and people with weakened immunity. Vaccination is the principal means of prevention, while surveillance and high immunization coverage help limit outbreaks.
Updated 21 Oct 2026
Medicine
Nipah virus
Nipah virus (NiV) is a zoonotic virus carried naturally by fruit bats of the family Pteropodidae. Human infection can follow contact with infected animals or contaminated food, and can also spread between people through close contact. Illness ranges from asymptomatic infection to respiratory disease and encephalitis. The World Health Organization estimates an outbreak case-fatality rate of 40%–75%, varying with outbreak and access to care. There is no licensed vaccine or specific treatment; early diagnosis and supportive medical care are central to management. Since its first recognized outbreak in Malaysia and Singapore in 1998–1999, cases have occurred in several South and Southeast Asian countries, including recurrent outbreaks in India and Bangladesh.
Updated 1 Nov 2026
Medicine
Oral rehydration therapy
Oral rehydration therapy (ORT) replaces water and electrolytes lost through diarrhoea, vomiting or similar illnesses by giving an oral rehydration solution (ORS). ORS is a glucose–electrolyte mixture designed to promote intestinal absorption of sodium and water. It is a first-line treatment for many cases of dehydration, although people with severe dehydration or inability to drink may need urgent intravenous treatment.
Updated 19 Oct 2026
Medicine
Palliative care
Palliative care is person-centred care that aims to relieve suffering and improve quality of life for people living with serious illness, as well as supporting their families and caregivers. It addresses physical symptoms and psychological, social, and spiritual needs; it can be provided alongside treatment for the illness, while end-of-life care is one part of its broader scope.
Updated 18 Oct 2026
Medicine
Parkinson's disease
Parkinson's disease is a progressive disorder of the nervous system that affects movement and can also involve sleep, mood, cognition, pain and other functions. It is associated with the loss of dopamine-producing nerve cells in the brain, although the causes of this loss are not fully understood. Symptoms and progression vary; treatments can ease some problems, but there is currently no cure.
Updated 16 Oct 2026
Medicine
Placebo effect
The placebo effect refers to changes in symptoms or other health outcomes associated with the context of receiving an intervention, rather than with its specific active ingredient or procedure. Expectations, learning, communication and the clinical setting can contribute to these responses. Improvement observed in a placebo group is not automatically a placebo effect: natural symptom changes, regression to the mean, reporting effects and other factors can also play a role.
Updated 30 Oct 2026
Medicine
Poliomyelitis
Poliomyelitis, commonly called polio, is a highly infectious disease caused by poliovirus. It spreads chiefly by the faecal–oral route; most infections cause no visible illness, but in a small proportion the virus affects the nervous system and can cause permanent paralysis. Vaccination has driven wild poliovirus down by more than 99% since the global eradication initiative began in 1988, although transmission has not been eliminated everywhere.
Updated 19 Oct 2026
Medicine
Scurvy
Scurvy is an illness caused by a severe, sustained lack of vitamin C (ascorbic acid). Because vitamin C is needed for the formation and repair of connective tissue, deficiency can cause fatigue, muscle or joint pain, bleeding gums, easy bruising and poor wound healing. The disease is uncommon where diets provide enough vitamin C, but can occur when food intake is severely restricted or nutritionally inadequate. It is preventable and treatable by restoring adequate vitamin C intake, with clinical care when needed.
Updated 22 Oct 2026
Medicine
Sickle cell disease
Sickle cell disease is a group of inherited blood disorders involving hemoglobin S, an abnormal form of the oxygen-carrying protein in red blood cells. Under some conditions, hemoglobin S makes red cells rigid and sickle-shaped; the cells can break down early and obstruct small blood vessels, causing anemia, painful episodes and damage to organs. Disease forms and severity vary. Newborn screening, preventive care and treatments such as hydroxyurea and blood transfusions can reduce complications, while stem-cell transplantation and gene-based therapies are options for some patients.
Updated 14 Oct 2026
Medicine
Thalassemia
Thalassemia is a group of inherited blood disorders in which changes affecting alpha- or beta-globin reduce the body's production of normal hemoglobin. The resulting anemia ranges from absent or mild symptoms in some carrier forms to serious disease that may require continuing care. Different genes and combinations of variants produce distinct forms and levels of severity, so thalassemia is not a single uniform condition.
Updated 20 Oct 2026
Medicine
Tuberculosis
Tuberculosis (TB) is an infectious disease caused mainly by the bacterium Mycobacterium tuberculosis. It most often affects the lungs and spreads through the air from people with infectious lung or throat disease. Infection does not always cause illness: latent or inactive TB has no symptoms and is not contagious, while active TB disease can damage the lungs or other organs and may spread to others. Testing, appropriate antibiotic treatment and preventive measures can reduce illness and transmission, although drug-resistant TB remains a serious challenge.
Updated 13 Oct 2026
Medicine
Vaccination
Vaccination is the administration of a vaccine to help the immune system recognize and resist a particular infection. Vaccines expose the body to a harmless form or component of a pathogen, or instructions for making a component, prompting immune responses that can include antibodies and immune memory. Their use has helped prevent disease in individuals and communities, and a coordinated vaccination and surveillance campaign led to the eradication of smallpox.
Updated 12 Oct 2026