Cardiology is the diagnosis and management of diseases which affect the heart and circulatory system. Cardiologists conduct investigations and help patients to manage a variety of heart disorders including rhythm disturbances, arterial blockages, angina, heart attacks, heart failure, and valvular heart disease. Routine physical examinations may reveal irregularities. Chest discomfort or palpitations are usually the first critical symptoms that lead patients to cardiologists. Generally, cardiac evaluation begins with a complete history and physical examination. An electrocardiogram, chest X–ray and blood tests are performed. 24 hour ambulatory monitoring, exercise stress testing, nuclear cardiac studies, echocardiography and cardiac catheterization procedures may be recommended. Heart After a diagnosis has been established, the cardiologist may suggest diet and activity modification, medical therapy, and in some cases procedures such as coronary artery balloon angioplasty or cardiac surgery. For all patients with heart disease, appropriate follow–up is vital. Most patients have a personal physician who may have instituted their initial evaluation and will play an important role in follow–up of their cardiac condition and general health. A vascular disorder is a blood vessel problem such as poor circulation caused by blockage. Arterial blocks could be in the coronary artery (the one that supplies blood to the heart, and which is dealt with exclusively by cardiac surgeons),the carotid artery (which supplies blood to the brain), the subclavian axillary brachial (to the upper limbs), and the iliac femoral popliteal (to the lower limbs). Even the veins can get blocked. Blocks in the blood vessels occur when narrowing takes place. Cholesterol and nicotine deposits, stress, diabetes and increased longevity are the most common causes of these blocks. A tingling sensation in the limbs, pain in the legs on walking, momentary loss of power in limbs, transient loss of vision are all signs of possible blocks in the arteries. The color Doppler test, is a non–invasive method for testing. It is 80 to 85% accurate and can give one an idea of how much the blood vessels are blocked.