Some blood disorders that cause easy or unexplained bruising include leukemia, factor X deficiency, idiopathic thrombocytopenic purpura, hemophilia and acquired platelet function disorder, according to Healthline. Unexplained or easy bruising is the result of small capillaries just under the skin breaking and blood leaking into the surrounding tissue, causing discoloration.
Leukemia, a cancer of blood-forming tissues such as the lymphatic system and bone marrow, typically affects the white blood cells, whose main function is to protect the body from infection, states Mayo Clinic. Symptoms of leukemia include easy bleeding, fatigue, frequent infections, unexplained weight loss, and bone pain or tenderness. Early symptoms of leukemia are often not noticeable, as they often mimic those of the flu and other common illnesses.
Factor X deficiency occurs when a person does not have enough of a specific protein in the blood, according to Healthline. The protein, factor X, plays an important role in blood clotting. A person who has factor X deficiency commonly has symptoms that accompany easy bruising, including bleeding from the mouth, nosebleeds, and severe bleeding following surgery or trauma.
Idiopathic thrombocytopenic purpura, or ITP, is a bleeding disorder that occurs when the immune system produces antibodies that work against the patient's own platelets, states MedlinePlus. A person with this disorder has symptoms such as heavy menstruation, bleeding in the mouth, nosebleeds and bleeding into the skin, along with bruising easily.