Diagnosis

Diagnosing vasovagal syncope often begins with a physical examination. During the physical exam, your doctor will listen to your heart and take your blood pressure. He or she may also massage the main arteries in your neck to see if that causes you to feel faint.

Your doctor may also recommend several tests to rule out other possible causes of your fainting — particularly heart-related problems. These tests may include:

• Electrocardiogram. This test records the electrical signals your heart produces. It can detect irregular heart rhythms and other cardiac problems. You may need to wear a portable monitor for at least a day or as long as a month.
• Echocardiogram. This test uses ultrasound imaging to view the heart and look for conditions, such as valve problems, that can cause fainting.
• Exercise stress test. This test studies heart rhythms during exercise. It's usually conducted while you walk or jog on a treadmill.
• Blood tests. Your doctor may look for conditions, such as anemia, that can cause or contribute to fainting spells.
• Tilt table test. If no heart problems appear to cause your fainting, your doctor may suggest that you undergo a tilt table test. During the test, you lie flat on your back on a table that changes positions, tilting you upward at various angles. A technician monitors your heart rhythms and blood pressure during the test to see if changing your posture affects them.