Medicine

Tumors of the hematopoietic and lymphoid tissues Overview of tumors arising in blood-forming and lymphoid tissues, including types, causes, diagnosis, treatment options, history, and how they differ from solid tumors.

Tuskegee Syphilis Study (1932–1972) Tuskegee syphilis experiment A United States Public Health Service study that observed untreated syphilis in Black men. The study became a landmark case in research ethics after subjects were misled and denied…

Tympanic membrane (eardrum): structure, function and clinical significance Tympanic membrane The tympanic membrane, or eardrum, is a thin, semi-transparent membrane separating the external ear from the middle ear that transmits sound vibrations to the ossicles and plays a…

Type 1 diabetes Type 1 diabetes is an autoimmune condition in which the pancreas fails to make sufficient insulin. It requires lifelong insulin replacement and careful glucose management to preven…

Type 2 diabetes A chronic metabolic condition characterized by insulin resistance and high blood glucose; covers causes, symptoms, complications, diagnosis, management, and public health aspects.

Typhoid (typhoid fever) Typhoid Typhoid is a systemic infectious disease caused by Salmonella enterica serovar Typhi, spread by contaminated food or water; it causes prolonged fever, abdominal symptoms, and can b…

Typhus: causes, forms, symptoms, history, and prevention Typhus Typhus is a group of vector-borne infectious diseases caused by rickettsial organisms. This article explains types, transmission, symptoms, treatment, historical impact, and distin…

Ulcer (open wound and mucosal lesion) Ulcer An ulcer is an open sore on the skin or a mucous membrane. This article explains types, causes, symptoms, diagnosis, treatment, prevention, and notable distinctions.

Underweight: Definition, Causes, Risks and Management Underweight Underweight describes having a body mass below common healthy expectations, often assessed by BMI. This article explains measurement, causes, health effects, diagnosis and approach…

Universal Health Care: meaning, models, benefits, and challenges Universal health care Overview of universal health care, its core principles, common financing models, history, benefits and challenges, and how it differs from related concepts.

Unsafe abortion: causes, risks, and public health responses Unsafe abortion Unsafe abortion is termination performed by untrained providers or in unhygienic settings; it contributes substantially to maternal illness and death and is addressed by clinical c…

Uremia: causes, symptoms, diagnosis, and management Uremia Uremia is the clinical syndrome that results when kidney failure allows waste products to accumulate in the blood, producing systemic symptoms managed by dialysis, transplantation,…

Ureter: structure, function, and clinical significance Ureter The ureter is a paired, muscular duct that carries urine from each kidney to the urinary bladder. This article summarizes anatomy, histology, physiology, common disorders, and clin…

Ureteral cancer Ureteral cancer is a rare malignancy of the ureters, most commonly an upper tract urothelial (transitional cell) carcinoma. This article covers presentation, diagnosis, treatment o…

Urethral cancer: types, symptoms, diagnosis, and treatment Urethral cancer An overview of urethral cancer, a rare malignancy of the urethra covering types, symptoms, diagnosis, treatment options, prognosis, and epidemiology.

Urinary tract infection (UTI): causes, symptoms, diagnosis and treatment Urinary tract infection A clear, concise guide to urinary tract infections: what they are, causes, common symptoms, diagnosis, treatment options, prevention and when to seek medical care.

Uterine cancer (womb cancer): types, diagnosis, treatment, and prevention Uterine cancer Comprehensive overview of cancers that arise in the uterus, covering major types, risk factors, common signs, diagnostic methods, treatment options, and prevention strategies.

Uvula (anatomy, function, and clinical significance) Uvula The uvula is the small conical tissue that hangs from the soft palate. This article reviews its anatomy, roles in speech and swallowing, clinical conditions, and surgical considera…

Vaccination: how vaccines work, types, history, and public health role Vaccination Vaccination primes the immune system to prevent infectious disease. This article explains mechanisms, main vaccine types, safety and development, historical milestones, uses, and k…

Vaccine: purpose, types, history, and public-health role Vaccine A vaccine is a biological preparation that trains the immune system to resist a specific infectious agent. This article explains how vaccines work, their varieties, history, uses,…

Vaginal cancer: types, signs, diagnosis, treatment and prevention Vaginal cancer A concise, neutral overview of vaginal cancer: its forms, symptoms, diagnosis, risk factors, treatments and prevention, with distinctions between primary and metastatic disease.

Vaginitis: causes, symptoms, diagnosis and treatment Vaginitis Vaginitis is inflammation of the vagina that commonly causes discharge, itching and pain. This article explains causes (infectious and noninfectious), diagnosis, treatments, preven…

Vaginoplasty: surgical creation or reconstruction of the vagina Vaginoplasty Comprehensive overview of vaginoplasty: indications, common techniques, history, risks, recovery and special considerations for congenital conditions and gender-affirming care.

Valproate: uses, forms, adverse effects, and safety considerations Valproate Overview of valproate (valproic acid and salts): clinical uses in epilepsy, bipolar disorder and migraine; common and serious adverse effects; pregnancy risks; monitoring, interact…

Varicose veins: causes, symptoms, diagnosis and treatment Varicose veins Enlarged, twisted superficial veins—most often in the legs—caused by faulty valves. Overview of causes, signs, diagnosis, conservative care, procedures and when to seek medical att…

Vasculitis: causes, classification, symptoms, diagnosis and treatment Vasculitis Vasculitis is inflammation of blood vessel walls that can damage organs. This article summarizes types, causes, clinical features, diagnostic approach, treatment principles and pra…

Vasodilation: mechanisms, physiological roles and clinical importance Vasodilation Vasodilation is the widening of blood vessels by relaxation of vascular smooth muscle. This entry covers mechanisms, physiological roles, common drug classes, measurement and key d…

Ventricular tachycardia (VT): overview, causes, and management Ventricular tachycardia Ventricular tachycardia (VT) is a rapid heart rhythm arising in the ventricles. This article explains its mechanisms, clinical features, diagnosis, emergency risks, and common trea…

Vertical transmission (mother-to-child transmission) Vertical transmission Transfer of infectious agents from a pregnant person to the fetus or newborn — modes, common pathogens, prevention, outcomes and historical context.

Vertigo: causes, symptoms, diagnosis, and management Vertigo Vertigo is the false sensation of motion or spinning caused by dysfunction of the vestibular system or central pathways. This article explains features, common causes, diagnosis, a…

Veterinarian: roles, education, specialties, and public health importance Veterinarian Overview of veterinarians: what they do, common specialties and workplaces, education and licensing pathways, history, public‑health roles, and contemporary challenges such as welf…

Veterinary Medicine: Practice, Scope, and Public Health Role Veterinary medicine Study and practice of preventing, diagnosing and treating disease in animals; covers clinical care, specialties, public health (zoonoses), food safety, research and animal welfare.

VIPoma (Verner–Morrison syndrome): causes, symptoms, diagnosis and treatment VIPoma A rare pancreatic neuroendocrine tumor that secretes vasoactive intestinal peptide (VIP), causing watery diarrhea, electrolyte loss and acid suppression. Overview of causes, signs,…

Laboratory virus culture techniques for detecting infectious, replication-capable viruses Viral culture Overview of laboratory virus culture techniques used to detect live, replication-capable viruses, covering traditional and shell vial methods, diagnostic uses, advantages, limitati…

Viral hemorrhagic fevers Viral hemorrhagic fever A group of viral illnesses that can cause fever, bleeding and multi-organ dysfunction. Includes Ebola, Lassa, hantavirus and others; transmitted from animals, vectors or person-to-…

Viral meningitis — causes, symptoms, diagnosis, treatment, and prognosis Viral meningitis Viral meningitis (aseptic meningitis) is inflammation of the membranes around the brain and spinal cord caused by viruses. Overview of causes, symptoms, diagnosis, treatment, preve…

Vitamin C (ascorbic acid): roles, sources, deficiency, and biological context Vitamin C Vitamin C, or ascorbic acid, is a water‑soluble vitamin vital for collagen production, antioxidant activity, wound healing and preventing scurvy; found in fruits and vegetables and…

Vitamin E: forms, functions, food sources, uses, and safety Vitamin E Fat‑soluble vitamin (tocopherols and tocotrienols) with antioxidant roles. Found in vegetable oils, nuts, seeds and greens; used in skin products and food preservation. Supplements…

Vitamin K: functions, forms, dietary sources and clinical importance Vitamin K Overview of vitamin K, a fat‑soluble nutrient essential for blood clotting, bone and vascular health; covers forms, absorption, dietary sources, deficiency risks, clinical uses, an…

Vitiligo: causes, appearance, diagnosis and management Vitiligo Vitiligo is a long-term skin condition in which patches of skin lose pigment due to melanocyte loss. This article explains signs, likely causes, diagnosis, treatments and social ef…

Vomiting (Emesis): Causes, Mechanism, Complications and Care Vomit Vomiting (emesis) is forceful expulsion of stomach contents through the mouth. This article explains causes, physiology, risks, basic treatment and when to seek medical care.

Vulvar cancer — causes, symptoms, diagnosis, and treatment Vulvar cancer Neutral overview of vulvar cancer: anatomy, common types, risk factors, signs, diagnosis, treatment options, prevention and how it differs from other gynecologic cancers.

Waist: anatomy, measurements, cultural and health significance Waist The waist is the narrow region of the torso between the rib cage and hips. This article describes its anatomy, measurement methods, cultural and clothing roles, and health implicat…

Walter Reed National Military Medical Center A leading U.S. Department of Defense medical center in Bethesda, Maryland; tri-service tertiary care, research, and presidential medical support center formed by a 2011 merger.

Warfarin: mechanism, medical uses, risks, and history Warfarin Warfarin is an oral anticoagulant and rodenticide that inhibits vitamin K–dependent clotting factors. It prevents and treats thromboembolic disease but requires careful monitoring…

Wart (skin growth caused by human papillomavirus) Wart A wart is a benign skin growth caused by human papillomavirus (HPV). This article explains appearance, types, causes, transmission, diagnosis, treatments, prevention and notable di…

Wilms tumor (nephroblastoma) Wilms tumor Wilms tumor, or nephroblastoma, is the most common kidney cancer of early childhood. It typically affects toddlers and has a high cure rate with combined surgery, chemotherapy and…

Windburn: myth, causes, symptoms and prevention Windburn Windburn is a common term for reddened, sore or chapped skin after outdoor exposure. Most cases are sunburn (UV damage); wind mainly increases dryness and irritation. Learn causes,…