Bleeding into the skin can occur from broken blood vessels that form tiny red dots (called petechiae). Blood also can collect under the tissue in larger flat areas (called purpura), or in a very large bruised area (called an ecchymosis).
Ecchymoses; Skin spots - red; Pinpoint red spots on the skin; Petechiae
Aside from the common bruise, bleeding into the skin or mucous membranes is a very significant sign and should always be checked out by a health care provider.
Redness of the skin (erythema) should not be mistaken for bleeding. Areas of bleeding under the skin do not become paler (blanch) when you press on the area, like the redness from erythema does.
Many things can cause bleeding under the skin. Some of them are:
Ballas M, Kraut EH. Bleeding and bruising: a diagnostic work-up. Am Fam Physician. 2008 Apr 15;77(8):1117-24.
Hayward CPM. Clinical approach to the patient with bleeding or bruising. Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 130.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.