ecchymosis
Meaning of ecchymosis: The flat purple patch left when blood escapes under the skin, larger than a pinpoint spot and free of any lump.
Definition of ecchymosis
Ecchymosis is a flat area of discoloration produced when blood leaks from damaged vessels into the skin or the lining of the mouth. It is the medical name for a bruise larger than about a centimeter across, and the skin over it stays level rather than raised. The color shifts through several shades over days as the trapped blood is broken down.
How does it differ from petechiae, purpura and a hematoma?
All four describe blood that has escaped its vessel, and they are separated by size and by whether anything can be felt. The distinction is not fussiness. Pinpoint spots and large flat patches carry different meanings.
| Term | Size | Raised |
|---|---|---|
| Petechiae | Pinpoint, a millimeter or two | No |
| Purpura | A few millimeters to about a centimeter | Sometimes |
| Ecchymosis | Larger than about a centimeter | No |
| Hematoma | Any size | Yes, a swelling that can be felt |
Why does the color change?
The colors are the breakdown of hemoglobin happening in slow motion under the skin. Fresh blood outside a vessel looks red, then dark purple as its oxygen is used up. Scavenging cells move in and convert the pigment, first to a green compound, then to a yellow brown one, before the last of it is carried away. That sequence is why a bruise passes through purple, green and yellow before fading, and why a bruise several days old looks nothing like a fresh one.
When does bruising carry weight?
Bruising after a knock is expected. What draws attention is bruising without a remembered injury, bruises far larger than the force involved, bruises in places rarely struck, or bruising alongside bleeding gums and nosebleeds. Drugs that thin the blood, a low platelet count, liver disease and inherited clotting problems all make a leaking blood vessel harder to seal. Skin itself matters too: long term steroid use and aging both thin the supporting tissue around small vessels, so ordinary contact produces striking bruises on the forearms. The position of a bruise can also point to an injury underneath, as with discoloration around both eyes or behind the ear after a head injury.
Also known as
Used in a sentence
Extensive ecchymosis was noted over the left flank two days after the fall.
Good to know
Ecchymosis names the large flat bruise, pinpoint spots are petechiae and a raised collection of blood is a hematoma, and it is bruising without a matching injury that carries the most meaning.
Word origin
Where “ecchymosis” comes from
From the Greek ek, meaning out, and chymos, meaning juice, describing a pouring out beneath the surface.