Many surgeons order routine lab tests before you are admitted to the hospital or before certain outpatient procedures. The tests help find possible problems that might complicate surgery if not found and treated early. Some of the most common tests done before surgery include:

• Chest X-rays. X-rays can help diagnose causes of shortness of breath, chest pain, cough, and certain fevers. They can also help diagnose abnormal heart, breathing, and lung sounds.

• Electrocardiogram (ECG). This test records the electrical activity of the heart. It shows abnormal rhythms (arrhythmias or dysrhythmias), finds heart muscle damage, and helps find the cause of chest pain, fluttering heartbeats (palpitations), and heart murmurs.

• Urinalysis. This test can help diagnose kidney and bladder infections, and diabetes. Certain types of urinalysis can also find illegal drugs in the body.

• White blood count. This test can help diagnose certain fevers and infections. It can also find out if a person is using medicines that affect white blood counts.

You may also need one or more of the following blood tests before surgery:

• Glucose. This test measures your blood sugar levels.

• Potassium. This test measures the amount of potassium, sodium, and other electrolytes in your blood. These chemicals help regulate heart rhythms and other body functions.

• Complete blood count (CBC). This test checks for a low number of red blood cells (anemia) and infection.

• Coagulation studies (PT/PTT). These tests find out how well your blood clots.

Talk with your doctor if you have questions or concerns about any of the tests he or she orders for you.