Medicine

Cleanliness: meanings, practices, history and public-health importance Cleanliness Overview of cleanliness: definitions, common methods (washing, detergents), scientific background, historical development, public-health impact (handwashing, cleanrooms) and notabl…

Clear Cell Sarcoma of the Kidney (CCSK) Clear cell sarcoma of the kidney A rare pediatric renal malignancy characterized by clear cytoplasm, distinct pathology, potential for late relapse, and propensity to metastasize to bone and lung; requires multimo…

Clear-cell sarcoma (soft tissue) Clear-cell sarcoma A rare malignant soft-tissue tumor with melanocytic features, usually arising in tendons or deep dermis of young adults; notable for recurrence, metastatic risk, and a characterist…

Clinic (medical facility) Clinic A clinic is an outpatient medical facility offering diagnosis, treatment, and preventative care. Clinics vary by size, specialty, staffing, ownership and their role within local he…

Clinical Institute Withdrawal Assessment for Alcohol (CIWA) Clinical Institute Withdrawal Assessment for Alcohol CIWA (often CIWA‑Ar) is a clinician‑rated scale that quantifies the severity of alcohol withdrawal using ten symptoms to guide monitoring and treatment decisions.

Clinical thermometer Medical instrument for measuring human body temperature; types, design, history, usage, accuracy, and safety considerations.

Clinical trial A clinical trial is a structured research study that evaluates safety and effectiveness of medical treatments, devices, or procedures in people under controlled conditions.

Clonazepam: clinical overview, pharmacology, uses, and safety Clonazepam Clonazepam is a benzodiazepine anticonvulsant and anxiolytic used for certain seizure types, panic disorder, and some sleep disturbances. It has sedative effects and a risk of depe…

Clostridium difficile (C. difficile): bacteria, disease, and public health Clostridium difficile Overview of Clostridium difficile: microbiology, how it causes disease, history and spread in healthcare settings, clinical features, prevention and treatment considerations.

Cluster headache: causes, symptoms, diagnosis and treatment Cluster headache Cluster headache is a severe, unilateral headache disorder with brief, frequent attacks and autonomic signs. This article explains features, suspected causes, diagnosis, acute and…

Cocaine Cocaine is a potent stimulant made from coca leaves; used recreationally for its energizing and euphoric effects and, in limited medical settings, as a topical anesthetic. It carri…

Codeine: uses, chemistry, pharmacology and safety Codeine Codeine is an opiate alkaloid used for mild-to-moderate pain, cough suppression and diarrhoea; it occurs in opium and is commonly produced from morphine and sold in several salt fo…

Coeliac disease (celiac disease) Coeliac disease Autoimmune disorder triggered by gluten that damages the small intestine, causes malabsorption and varied symptoms; diagnosed by serology and biopsy and managed with a lifelong glu…

Colitis: causes, symptoms, diagnosis, and treatment Colitis Colitis is inflammation of the large intestine. This article explains types, common signs, diagnostic approaches, management options, complications and lifestyle measures.

Colorectal cancer: overview, signs, causes, diagnosis and management Colorectal cancer Colorectal cancer is a malignancy of the colon or rectum. This article summarizes its characteristics, symptoms, risk factors, screening, diagnosis, treatment options and preventio…

Coma: overview, causes, clinical features, treatment and legal aspects Coma Coma is a prolonged state of deep unconsciousness caused by injury, disease, intoxication or metabolic disturbance. This article explains causes, clinical signs, diagnosis, care, p…

Combat stress reaction Combat stress reaction is an acute psychological and physiological response to the trauma of combat, often treated early near the front to prevent chronic conditions such as PTSD.

Common cold: causes, symptoms, transmission, and prevention Common cold A concise guide to the common cold: viral causes, typical symptoms, how it spreads, preventive measures, treatment options, complications and basic epidemiology.

Comorbidity: co-occurring medical and psychiatric conditions Comorbidity Comorbidity describes the presence of one or more additional disorders co-occurring with a primary condition. This article explains definitions, causes, examples, clinical signific…

Medication compliance and adherence in medicine Compliance (medicine) Overview of medication compliance (adherence): definitions, measurement, causes, clinical consequences and strategies to improve long-term treatment adherence in chronic disease ca…

Complication (medicine) Complication A medical complication is an unintended, unfavorable development that makes a disease or its treatment harder to manage; it can arise from the illness itself, from therapies, or fr…

Concussion: causes, symptoms, diagnosis, treatment and prevention Concussion A concussion is a common, usually reversible brain injury caused by a blow or jolt to the head. This article explains symptoms, management, recovery, prevention and how it differs…

Condom (barrier contraceptive and STI prevention) Condom A condom is a barrier sheath used during sexual activity to reduce pregnancy and lower the risk of sexually transmitted infections; available in several materials and designs and i…

Conjunctivitis (Pinkeye): Causes, Symptoms, Diagnosis, and Treatment Conjunctivitis Conjunctivitis, or pinkeye, is inflammation of the conjunctiva. This article explains types, causes, symptoms, diagnosis, treatment, prevention, and when to seek medical care.

Constipation: causes, symptoms, stool types, treatment and prevention Constipation Comprehensive overview of constipation: definition, common causes, stool types, diagnosis, management, prevention, complications, and when to seek medical care.

Contact lens: overview, types, history, uses, care and risks Contact lens Contact lenses are thin optical lenses placed on the eye to correct vision or for cosmetic and therapeutic uses. This article explains types, fitting, care, history, benefits and s…

Cornea: Structure, Function, and Clinical Importance Cornea Transparent, avascular front tissue of the eye that provides most refractive power; layered microstructure, physiology, common diseases, and surgical treatments central to vision.

Coronary artery bypass surgery (CABG) Coronary artery bypass surgery Surgical treatment for blocked coronary arteries that restores blood flow to the heart by grafting vessels from elsewhere on the body; commonly called CABG or heart bypass.

Coronary artery disease: causes, symptoms, diagnosis and prevention Coronary artery disease An accessible overview of coronary artery disease, its causes and progression, common symptoms and diagnostic tests, treatment options, prevention strategies, and notable distincti…

Coronavirus disease 2019 (COVID-19) Coronavirus disease 2019 Infectious disease caused by SARS-CoV-2, first identified in late 2019. Clinical spectrum ranges from no symptoms to severe respiratory and systemic illness; global pandemic respon…

Cortisone: steroid hormone, medical uses, metabolism, and risks Cortisone Cortisone is a steroid hormone produced by the adrenal cortex and a medication used for its anti-inflammatory and immunosuppressive effects; it is closely related to cortisol and h…

Cough: causes, types, diagnosis and management Cough An accessible overview of cough: how it works, common causes, types (acute, subacute, chronic), evaluation, treatments and when to seek medical care.

COVID-19 pandemic in Afghanistan: overview, response, and impacts COVID-19 pandemic in Afghanistan Summary of the arrival, public health response, and social and economic effects of the COVID-19 pandemic in Afghanistan, including timeline, challenges, and recovery efforts.

COVID-19 pandemic in Bulgaria: overview, response, and impacts COVID-19 pandemic in Bulgaria Summary of the spread, public-health measures, societal and economic effects, and notable features of the COVID-19 pandemic in Bulgaria since first confirmation in March 2020.

COVID-19 pandemic in Chile Overview of the COVID-19 pandemic in Chile: timeline, public health response, social and economic effects, vaccination rollout and notable developments through subsequent waves.

COVID-19 pandemic in Denmark Overview of the COVID-19 pandemic in Denmark: timeline, public-health response, impacts, testing and vaccination, notable events (including the 2020 mink cull) and distinctions.

COVID-19 pandemic in North Macedonia Overview of how the SARS‑CoV‑2 pandemic affected North Macedonia: timeline, public-health response, social and economic impacts, vaccination rollout, and lasting effects.

COVID-19 pandemic in Portugal Summary of the COVID-19 pandemic in Portugal: emergence in March 2020, national health response, public measures, vaccination rollout, social and economic impacts, and notable regi…

COVID-19 pandemic in Serbia A concise overview of the COVID-19 pandemic in Serbia: spread and public-health response, social and economic effects, vaccination efforts, and notable aspects of national manageme…

COVID-19 pandemic in South Africa Overview of the arrival, public-health response, variants, vaccination rollout and social impacts of the COVID-19 pandemic in South Africa.

COVID-19 pandemic in the Central African Republic Overview of how the global COVID-19 pandemic reached and affected the Central African Republic, its health system challenges, response measures, humanitarian implications, and nota…

COVID-19 pandemic in Turkey Summary of the introduction, spread, public-health response, social and economic effects, and notable issues during the COVID-19 pandemic in Turkey.

COVID-19 testing: types, interpretation, and public-health roles COVID-19 testing Overview of SARS-CoV-2 testing: molecular and antibody tests, how they work, accuracy and limitations, uses for diagnosis and surveillance, and the role of testing in estimating mo…

COVID-19 vaccine: types, development, rollout, and global impact COVID-19 vaccine Overview of vaccines developed to prevent COVID-19, their main types, regulatory milestones, rollout strategies, effectiveness, safety considerations, and global challenges.

Cowpox: virus, hosts, history and clinical features Cowpox Cowpox is an uncommon orthopoxvirus infection of animals and humans. This article explains the virus, typical hosts and transmission, clinical signs, historical role in vaccination…

Cremaster muscle Thin skeletal muscle layer surrounding the testis and spermatic cord that elevates the testes for temperature regulation and protection; involved in the cremasteric reflex.

Creutzfeldt–Jakob disease (CJD): causes, signs, diagnosis and prevention Creutzfeldt–Jakob disease Creutzfeldt–Jakob disease (CJD) is a rare, fatal neurodegenerative prion disorder. This article outlines its forms, pathology, symptoms, diagnosis, transmission risks, prevention a…

Crohn's disease: overview, symptoms, causes, diagnosis and management Crohn's disease Crohn's disease is a chronic inflammatory condition of the digestive tract. This article summarizes its presentation, probable causes, diagnostic approach, treatment options, histo…