Some Disorders & Diseases of the Circulatory System ANEMIA a condition in which there is a decrease in hemoglobin or in the number of erythrocytes ANEURYSM a permanent stretching of an artery or heart chamber; caused by the pressure of blood on muscular walls weakened by disease or injury ARRHYTHMIA an irregularity of the heartbeat BRUISE results from broken blood capillaries in the skin and underlying tissue. The diffusion and breaking down of blood causes the "black and blue" marks. HEMORRHAGE a break in a blood vessel resulting in loss of blood it may be due to physical injury or disease LEUKEMIA a disease characterized by an increase in the number of leukocytes. It is usually fatal but in some cases has been brought under control. STROKE a sudden loss of consciousness caused by a hemorrhage or a blood clot in arteries in or around the brain VARICOSE VEINS veins that are distended, swollen, and knotted. They are more common in people who stand for long period of time.