Health Glossary

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

Sanitation

The systems, practices, and infrastructure used to safely manage human waste and maintain conditions that reduce exposure to disease-causing contaminants.…
View Definition →

Sarcoma

A sarcoma is a malignant tumor arising from connective, supporting, or other non-epithelial tissues such as bone, muscle, fat, cartilage,…
View Definition →

Scar

A scar is an area of fibrous tissue that replaces normal tissue as part of the body’s healing process after…
View Definition →

Sebum

A natural oily substance produced by sebaceous glands that helps lubricate, waterproof, and protect the skin and hair. Sebum contains…
View Definition →

Seizure

A seizure is a temporary episode of abnormal, excessive, or synchronized electrical activity in the brain that can cause changes…
View Definition →

Sepsis

A life-threatening condition caused by a dysregulated response to an infection that results in organ dysfunction. Sepsis occurs when the…
View Definition →

Septic Shock

A life-threatening form of sepsis in which abnormalities in circulation and cellular metabolism lead to persistent inadequate tissue perfusion and…
View Definition →

Severe

Describing a disease, condition, symptom, or abnormality that is particularly intense, extensive, or medically serious. Severe is a clinical descriptor…
View Definition →

Sinus

A sinus is a cavity, channel, or space within the body, often referring to one of the air-filled spaces connected…
View Definition →

Sinusitis

Sinusitis is inflammation of one or more of the air-filled spaces, called paranasal sinuses, around the nose. Sinusitis can cause…
View Definition →

Skin

The skin is the body’s largest organ and forms a protective covering that contributes to sensation, temperature regulation, immune defense,…
View Definition →

Sterile

Sterile describes a state in which no viable microorganisms are present, according to the applicable sterility standard or validated process.…
View Definition →

Stress

A state or response that occurs when a person perceives that demands, challenges, or threats exceed or strain their available…
View Definition →