Symptoms of blood disorders are often vague and nonspecific, that is, they could indicate a disorder of almost any part of the body. However, although no single symptom unmistakably indicates a blood disorder, certain groups of symptoms suggest the possibility. Such groups of symptoms most commonly relate to decreases in blood cells, such as a reduced number of red blood cells (anemia), a reduced number of white blood cells (leukopenia), or a reduced number of platelets (thrombocytopenia). For example, a person who has fatigue, weakness, and shortness of breath may have anemia. A person who has fever and infection may have too few white blood cells. A person who bleeds or bruises easily may have too few platelets.

Occasionally, symptoms may relate to increased numbers of blood cells. For example, people with thickened (more viscous) blood due to increased numbers of red blood cells (polycythemia) or white blood cells may experience symptoms such as shortness of breath, headaches, dizziness, and confusion. Blood can also become thickened because of an increased production of immune-related proteins, as in multiple myeloma.

Finally, disorders of substances (factors) responsible for normal blood clotting may result in insufficient blood clotting (manifesting as excessive bruising or bleeding or as small red or purple spots on the skin) or in the formation of abnormal blood clots (producing warm, painful areas in the legs or sudden shortness of breath, chest pain, or both). These problems may arise because the body does not produce enough of these factors, the factors are abnormal, or the body is using up the factors too quickly.

Last full review/revision May 2006 by Steven H. Kroft, MD