If you have a health problem, follow your doctor's guidelines. A needle is used to draw a small amount of blood from the arm. Sometimes a doctor may ask that you don't eat the night before taking a blood test. Many of the major risk factors for heart disease are largely within your control. Modifying these risk factors can dramatically reduce your risk of heart attack.
Blood tests are generally part of annual physical exams.
They may be needed more frequently, however, if you have heart disease or have symptoms like chest pain or shortness of breath. Routine blood tests are also used to measure how well medications are working and whether dosages should be adjusted. Also known as an EKG or ECG, a resting electrocardiogram records the electrical impulses that stimulate your heart to beat. Electrodes , or leads, attached to the arms, legs and chest detect electrical impulses as they move through the heart. A machine converts these impulses into a zigzag readout.