Medical Glossary

Common Medical Terms, Explained

Plain-language definitions of common medical terms used throughout iSymptom. This glossary is for general education and does not replace advice from a qualified healthcare professional.

Acute

Describes a condition that comes on suddenly and is usually short-lived, such as an acute infection. The opposite of chronic.

Atrophy

Wasting or shrinking of tissue, muscle, or an organ.

Benign

Not cancerous. A benign growth does not spread to other parts of the body, though it may still need treatment.

Bilateral

Affecting both sides of the body; unilateral means one side only.

Chronic

A condition that lasts a long time, often months or years, and may need ongoing management, such as chronic high blood pressure.

Comorbidity

The presence of more than one condition in the same person at the same time.

Congenital

Present from birth, whether inherited or caused by events during pregnancy.

Contraindication

A reason that a treatment should not be used because it may be harmful.

Diagnosis

Identifying a disease or condition from its signs, symptoms, and test results.

Differential diagnosis

The list of possible conditions that could explain a person's symptoms.

Edema

Swelling caused by excess fluid trapped in the body's tissues, often in the legs, ankles, or feet.

Embolism

A blockage of a blood vessel by a clot, air bubble, or other material that has traveled through the bloodstream.

Etiology

The cause or origin of a disease or condition.

Hemorrhage

Heavy or uncontrolled bleeding, either external or internal.

Hereditary

Passed from parents to children through genes.

Hypertrophy

Enlargement of tissue or an organ from increased cell size.

Idiopathic

Of unknown cause. An idiopathic condition arises without an identifiable reason.

Inflammation

The body's response to injury or infection, causing redness, warmth, swelling, and pain.

Ischemia

Reduced blood flow to a part of the body, depriving tissue of oxygen.

Lesion

Any area of abnormal tissue, such as a sore, ulcer, growth, or wound.

Localized

Limited to one specific area of the body.

Malignant

Cancerous. Malignant cells can invade nearby tissue and spread to other parts of the body.

Necrosis

The death of body tissue, usually from lack of blood supply or injury.

Neuropathy

Damage to nerves, often causing numbness, tingling, or pain, commonly in the hands and feet.

Palliative

Care focused on relieving symptoms and improving quality of life rather than curing disease.

Prognosis

The likely course and outcome of a disease, including the chance of recovery.

Prophylaxis

Treatment given to prevent disease rather than to treat it.

Recurrence

The return of a condition after treatment or a symptom-free period.

Relapse

The return of a disease or its symptoms after a period of improvement.

Remission

A period when the signs and symptoms of a disease are reduced or absent.

Sepsis

A life-threatening, body-wide response to infection that needs emergency care.

Sign

An objective finding a clinician can observe or measure, such as a rash or fever.

Symptom

Something a person experiences and reports, such as pain, fatigue, or nausea.

Syndrome

A group of signs and symptoms that consistently occur together.

Systemic

Affecting the whole body rather than a single organ or area.

Thrombosis

The formation of a blood clot inside a blood vessel.