What does edema mean?
Edema is the medical term for the abnormal buildup of fluid in the body's tissues, which produces visible or palpable swelling, most often in the feet, ankles, legs, or hands. It occurs when fluid leaks from blood vessels into surrounding tissue faster than the lymphatic system can drain it away. Common causes include prolonged standing or sitting, pregnancy, certain medications, heart failure, kidney disease, and liver disorders; pulmonary and cerebral edema — affecting the lungs and brain respectively — are more serious forms requiring urgent treatment. Doctors classify some cases as pitting edema, meaning an indentation briefly remains when pressure is applied. The word derives from the Greek oidēma, meaning 'swelling', and entered English in the seventeenth century via New Latin. In British English it is conventionally spelled oedema with an initial 'oe', while American usage prefers edema. Though technical rather than everyday vocabulary, edema is indispensable in medicine and health reporting.
nounA condition in which excess fluid accumulates in the body's tissues, causing swelling, most commonly in the legs, ankles, and feet. In British English it is spelled "oedema".
- Excess accumulation of serous fluid in the intercellular spaces of tissues, producing visible or palpable swelling (medicine).
"The patient's ankles showed noticeable edema after several days of bed rest."
"High altitude can trigger pulmonary edema, in which fluid collects in the lungs."
"The physician pressed a finger into the swollen ankle to test for pitting edema."
The plural is rarely used because edema is normally treated as an uncountable mass noun referring to a condition or phenomenon generally. When a count is needed, clinicians usually speak of specific types or sites of edema instead.
"The scan revealed multiple edemas across different organ systems, an unusually severe presentation."
Before doctors called it edema, they called it dropsy — and the ancient Greek word behind it literally means 'a swelling'.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of edema
Edema comes from the Greek oidēma, meaning 'swelling' or 'tumor', derived from the verb oidein, 'to swell'. It passed into English in the early modern period through New Latin as a learned medical borrowing, initially appearing as oedema before the simplified American spelling edema became standard in the United States. A true cognate is rare in everyday English, though the related Greek-derived medical term hydropsy shares the same semantic territory.
Related word forms
How edema is actually used
Primarily a medical term used in clinical and scientific registers. The spelling is "oedema" in British English and "edema" in American English. It is not typically used in casual conversation outside medical contexts.
Easily confused with edema
Edema is fluid accumulation causing tissue swelling, while edamame is a dish of immature soybeans.
An enema is a procedure of injecting liquid into the rectum; edema is pathological tissue swelling from retained fluid.