Edema

Etymology

From Greek “oidēma” (a swelling), from “oidein” (to swell). The same swelling-root lurks in the name Oedipus — “swollen foot.” Medicine kept the plain Greek noun because it describes precisely what the eye sees: tissue puffed up with fluid that should not be there.

noun · /ih-DEE-muh/
Swelling caused by excess fluid trapped in the body’s tissues.
What it names
The puffy, waterlogged swelling — of ankles, legs, or hands — that is less a disease in itself than a visible signal of something deeper, from a long flight to a failing heart.
Example
By the end of the long flight her feet were so swollen with edema that her shoes no longer fit.
Related idea
Edema is a symptom, not a diagnosis — the swelling points elsewhere, to the heart, kidneys, or veins. Treating the puffiness without asking what is causing it is like silencing an alarm without checking for the fire.