Medicine

Tardive dyskinesia Tardive dyskinesia is a movement disorder marked by involuntary, repetitive movements that typically appear after months or years of dopamine‑blocking drug exposure. This article c…

Tay–Sachs disease: causes, symptoms, inheritance and diagnosis Tay-Sachs disease An overview of Tay–Sachs disease: genetic causes, biochemical mechanism, clinical forms, screening, management and historical notes on incidence and prevention.

Temozolomide — oral alkylating chemotherapy for brain tumors Temozolomide An oral alkylating chemotherapy used chiefly for glioblastoma and anaplastic astrocytoma; crosses the blood–brain barrier, has predictable toxicities, and its benefit is influenced…

Tennis elbow (lateral epicondylitis): causes, symptoms and treatment Tennis elbow Tennis elbow (lateral epicondylitis) is pain at the outer elbow from overuse of forearm extensor tendons. This article covers causes, symptoms, diagnosis, treatments and prevention…

Tension headache (tension-type headache): causes, symptoms, and care Tension headache A common primary headache characterized by bilateral pressing or tightening pain. Covers symptoms, causes, typical course, treatment options, prevention, and when to seek medical c…

Teratogen: agents that cause developmental abnormalities Teratogen A teratogen is an agent that can disrupt prenatal development and increase the risk of congenital abnormalities. Causes, timing, examples, mechanisms, history, prevention, and publ…

Terminal illness: definition, care, and social and medical considerations Terminal illness An overview of terminal illness: what it means, common causes, how prognosis is determined, approaches to palliative care and hospice, ethical issues, and how definitions have chan…

Testicular cancer: overview, diagnosis, treatment, and prognosis Testicular cancer Testicular cancer affects one or both testicles, most often in males aged 15–40. It is usually highly treatable. This article covers types, symptoms, diagnosis, treatment, prognosi…

Testosterone: roles, synthesis, effects, and clinical significance Testosterone A comprehensive overview of testosterone: its biological synthesis, functions in males and females, physiological effects, clinical uses, disorders, and broader significance.

Tetanospasmin — the tetanus neurotoxin Tetanospasmin Tetanospasmin is the potent neurotoxin produced by Clostridium tetani; it causes the muscle rigidity and spasms of tetanus and is important in clinical care, prevention and neurosc…

Tetanus (lockjaw): causes, symptoms, prevention and treatment Tetanus Tetanus is a serious infectious disease caused by a neurotoxin from Clostridium tetani that produces sustained muscle contractions. It is vaccine-preventable but remains a threat w…

Tetracycline: a broad‑spectrum antibiotic Tetracycline Tetracycline is a family of broad‑spectrum antibiotics first isolated in the 1940s. It inhibits bacterial protein synthesis and remains important in medicine, with notable uses, ri…

Tetraplegia (Quadriplegia): causes, effects, levels, and care Tetraplegia Tetraplegia (quadriplegia) is paralysis affecting all four limbs and often the torso. This article explains causes, clinical features, injury levels, rehabilitation, and key distin…

Thalassaemia: causes, types, diagnosis, treatment and prevention Thalassaemia An accessible overview of thalassaemia — a hereditary blood disorder affecting haemoglobin — covering causes, classification, clinical features, diagnosis, treatment options and pu…

Thalidomide: history, risks, and modern medical uses Thalidomide Thalidomide is a drug first marketed as a sedative in the 1950s that caused widespread birth defects. It is now used in tightly controlled settings for select conditions such as le…

The Medical Journal of Australia: overview, history and role The Medical Journal of Australia A concise encyclopedia entry on The Medical Journal of Australia (MJA): its purpose, content types, history since 1914, publication and editorial role in Australian medicine and pu…

Therapeutic index A pharmacological measure comparing a drug’s toxic or lethal dose to its effective dose; used to express safety margins and guide monitoring of drugs with narrow therapeutic ranges…

Therapy: medical and psychological treatments, types and uses Therapy Comprehensive overview of therapy: meanings, common types (medical, psychological, physical), how therapies are delivered, history, benefits, risks, and distinctions from diagnosis…

Thiamine (Vitamin B1) Thiamine Thiamine, or vitamin B1, is a water-soluble B vitamin essential for cellular energy metabolism, nervous system function, and carbohydrate processing; deficiency causes disorders su…

Thigh (anatomy and function) Thigh The thigh is the region of the human leg between hip and knee, built around the femur and major muscles, nerves and vessels; essential for posture, locomotion and weight bearing.

Throat: structure, function and clinical significance Throat The throat is the passage linking the mouth and nasal cavities to the esophagus and airways. It supports swallowing, breathing and speech and contains the pharynx, larynx, tonsils…

Throat culture (pharyngeal swab test) Throat culture A throat culture is a laboratory test that detects bacteria or fungi causing pharyngeal infections. It explains collection, common organisms, interpretation, limitations and altern…

Thrombus (blood clot): formation, structure, and clinical significance Thrombus A thrombus is a blood clot formed during coagulation that seals damaged vessels; it can be protective or harmful when it blocks circulation. Overview, composition, clinical roles,…

Thyroid gland: structure, hormones, function, and clinical importance Thyroid Concise overview of the thyroid gland: anatomy, hormone synthesis (T4, T3, calcitonin), physiological roles, common disorders, diagnosis, treatment options and public health consid…

Thyroid cancer: types, diagnosis, treatment, and prognosis Thyroid cancer Concise encyclopedia overview of thyroid cancer covering the gland, major types, causes, diagnosis, treatments, outcomes, and notable distinctions.

Thyroid-stimulating hormone (TSH) Thyroid-stimulating hormone TSH (thyrotropin) is a pituitary glycoprotein hormone that regulates the thyroid gland, controlling production of T4/T3 and influencing metabolic rate; it is central to diagnosis a…

Tincture of iodine An alcohol-based antiseptic solution of elemental iodine and iodide used as a topical disinfectant and laboratory reagent; formulation, chemistry, uses, and safety considerations.

Tonic water Carbonated soft drink flavored with quinine and sweeteners, originally used as an antimalarial preventive and now commonly mixed with spirits or consumed as a bitter soft drink.

Tonsil (tonsils): structure, function, common conditions and treatment Tonsil Tonsils are paired masses of lymphoid tissue in the throat that help detect pathogens. This article describes types, immune roles, common diseases, diagnosis, treatment, and surgic…

Tonsillitis: causes, symptoms, diagnosis, treatment and complications Tonsillitis Tonsillitis is inflammation of the palatine tonsils, usually viral or bacterial. This article explains causes, symptoms, diagnosis, treatments (including tonsillectomy), prevention…

Toothache: causes, symptoms, diagnosis, treatment and prevention Toothache A toothache is pain originating in or around a tooth. This article explains common causes, symptoms, diagnosis, treatments, and practical prevention and when to seek urgent care.

Tourette syndrome: causes, symptoms, diagnosis and management Tourette syndrome Tourette syndrome is a neurodevelopmental condition marked by repeated motor and vocal tics starting in childhood. This article explains features, causes, diagnosis, treatments, pr…

Tourniquet (medical device) Tourniquet A tourniquet is a band or device tightened around a limb to stop arterial bleeding. Used in emergencies and surgery, it has specific application steps, risks, and types including i…

Toxic shock syndrome A rare but serious illness caused by bacterial toxins, most often from Staphylococcus aureus or Streptococcus pyogenes. Presents with fever, rash, low blood pressure and organ dysf…

Toxicology: principles, mechanisms, and applications Toxicology Toxicology examines how chemical agents damage living organisms, how hazards are measured, and how risks are managed across medicine, environment, and industry.

Tracheotomy and Tracheostomy: Procedure, Uses, History, and Care Tracheotomy Tracheotomy/tracheostomy creates a direct airway in the neck. This article explains definitions, techniques, indications, emergency use, history, complications, aftercare, decannul…

Trans man: definition, transition, history and social issues Trans man An overview of trans men—people assigned female at birth who identify as male—including terminology, transition steps, diversity of sexual orientation, history, challenges, and not…

Transplant (surgery): organs, tissues, donors, rejection and advances Transplant (surgery) Surgical transplantation replaces damaged organs or tissues with healthy ones from donors. Covers types, donor sources, immune rejection, matching, immunosuppression, risks, histor…

Trauma (physical injury): causes, types, clinical care and distinctions Trauma Trauma refers to physical injury from external forces. This article covers types, mechanisms, clinical recognition, emergency care and differences from psychological trauma, with c…

Trauma center A trauma center is a hospital unit prepared to provide immediate, multidisciplinary care for severe injuries around the clock and integrated into regional trauma systems.

Traumatic brain injury Traumatic brain injury (TBI) is damage to the brain caused by an external force. It ranges from mild concussion to severe, life‑changing injury and affects physical, cognitive, and…

Trench foot (immersion foot): causes, symptoms, treatment, and history Trench foot Trench foot is tissue injury of the feet from prolonged cold, wet exposure. This article explains causes, symptoms, prevention, treatment and its historical significance during tre…

Treponema pallidum: bacterium that causes syphilis and related treponematoses Treponema pallidum Overview of Treponema pallidum: biology, diseases (syphilis, yaws, bejel, pinta), diagnosis, treatment options, public health importance, and notable distinctions such as antibioti…

Trichomoniasis — cause, symptoms, diagnosis, treatment and prevention Trichomoniasis Trichomoniasis is a common sexually transmitted infection caused by the protozoan Trichomonas vaginalis. This article explains its biology, symptoms, diagnosis, treatment, and prev…

Trisomy: causes, types, diagnosis and clinical implications Trisomy Trisomy is a chromosomal condition in which three copies of a chromosome are present. This article explains mechanisms, common types, diagnosis, history and clinical considerations…

Trypanosomiasis: causes, forms, transmission, and control Trypanosomiasis Trypanosomiasis is a group of parasitic diseases caused by Trypanosoma species, affecting humans and animals; includes African sleeping sickness and American Chagas disease, with d…

Tuberculosis: causes, course, diagnosis, treatment and public health Tuberculosis Comprehensive overview of tuberculosis: cause, symptoms, transmission, diagnosis, treatment, prevention and historical background for a general audience.

Tularemia: causes, forms, diagnosis, and prevention Tularemia Tularemia is a zoonotic bacterial infection caused by Francisella tularensis, transmitted from animals or insect vectors to humans; it has diverse clinical forms and is treatable w…