Medical Dictionary

Health Glossary

Demystifying medical language. Browse or search for clear, human-centered explanations of common medical terms.

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Abdomen

The part of the body between the chest and the pelvis that contains organs such as the stomach, intestines, liver,…

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Abscess

A collection of pus caused by infection. Abscesses may develop in: They are often painful and swollen. Related:

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Acne mechanica

Acne mechanica is a type of acne that is triggered or worsened by repeated friction, pressure, heat, or rubbing against…

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Acne Vulgaris

Acne vulgaris is a common inflammatory skin condition in which hair follicles become blocked with sebum and dead skin cells,…

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Acute

A health problem that starts suddenly and usually lasts for a short time. An acute illness may appear quickly and…

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Airborne

Able to spread through tiny particles in the air. Some infections can spread when infected people: Related:

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Allergen

An allergen is a substance that can trigger an allergic reaction in susceptible individuals. Common allergens include pollen, pet dander,…

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Allergy

A reaction that happens when the immune system responds unusually to a substance that is normally harmless. Common triggers include:…

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Amino Acid

A small molecule used to build proteins in the body. Amino acids help with: Related:

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Anemia

A condition where the body does not have enough healthy red blood cells or hemoglobin to carry oxygen properly. People…

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Antibiotic Resistance

A situation where bacteria change over time and no longer respond well to antibiotics. This can make infections harder to…

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Antibiotic Resistance

A situation where bacteria no longer respond properly to antibiotics. This can happen when: Related:

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Antibiotics

Medicines used to treat infections which are caused by bacteria. Antibiotics do not work against viruses like the common cold…

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Antibody

A protective protein made by the immune system to help recognize and fight infections. Antibodies help the body respond to…

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Anxiety

A feeling of excessive worry, fear, or nervousness that may affect daily life. Anxiety can also cause physical symptoms such…

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Appetite

The desire to eat food. Changes in appetite may occur during: Related:

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Arrhythmia

An abnormal heartbeat rhythm. The heart may beat: Some arrhythmias are harmless, while others can become dangerous. Related:

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Artery

An artery is a blood vessel that carries blood away from the heart. Most arteries carry oxygen-rich blood to the…

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Arthritis

Inflammation affecting one or more joints. Arthritis may cause: Related:

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Asthma

A condition that affects the airways and makes breathing difficult. Asthma can cause: Symptoms may worsen during exercise, infections, dust…

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Autoimmune Disease

A condition where the immune system mistakenly attacks the body’s own tissues. Autoimmune diseases can affect: Examples include: Related:

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Autonomic Nervous System

The part of the nervous system that controls automatic body functions. It helps regulate: Related:

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Bacteria

Tiny living organisms that exist almost everywhere. Some bacteria are harmless or helpful, while others can cause infections. Examples of…

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Benign

Not cancerous and usually less dangerous than malignant disease. A benign tumor does not normally spread to other parts of…

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