Pitting edema is a type of peripheral edema in which pressing a swollen area leaves a temporary indentation or “pit.”

It occurs when excess fluid is present in the interstitial tissues and is commonly seen with heart failure, venous insufficiency, kidney disease, liver disease, or low blood protein states. MSD Manual description explains that finger pressure displaces the interstitial fluid, producing the pit.

Usually transudate.

Typical pitting edema from raised hydrostatic pressure or reduced plasma oncotic pressure, such as in heart failure, cirrhosis, nephrotic syndrome, or venous insufficiency, is protein-poor transudative edema.

But pitting describes the physical sign, not the fluid type. Inflammatory edema can be protein-rich exudate and may also occasionally pit. Robbins notes that edema itself can be either protein-poor transudate or protein-rich exudate.