1. Spider and Varicose Veins Slideshow Pictures
2. Deep Vein Thrombosis (DVT) Slideshow Pictures

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

View Full Profile

Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

View Full Profile

In this Article

• Introduction to fainting (syncope)
• What causes fainting (syncope)?
• Heart rhythm changes
• Heart structural conditions
• Heart valve conditions
• Sudden cardiac death
• Postural hypotension
• Vasovagal syncope
• Anemia
• Dehydration
• Orthostatic hypotension
• Vertebrobasilar system
• Electrolyte imbalance
• Other medications and drugs
• Pregnancy
• What are the signs and symptoms of fainting (syncope)?
• How is fainting (syncope) diagnosed?
• What is the treatment for fainting (syncope)?
• Can fainting (syncope) be prevented?
• Fainting (Syncope) At A Glance
• Patient Comments: Fainting - Describe Your Experience
• Patient Comments: Fainting (Syncope) - Treatments
• Patient Comments: Fainting (Syncope) - Causes
• Patient Comments: Fainting (Syncope) - Symptoms
• Fainting Index

As with most medical conditions, the history is the key in finding out why a patient faints. Since most episodes of syncope do not occur while the patient is wearing a heart monitor in front of a medical provider, it is the description of how the patient felt and what bystanders or family members witnessed that will give clues to the diagnosis.

Physical examination will try to look for signs that will give direction to the potential diagnosis. Heart monitoring may be done to look for heart rhythm disturbances. Blood pressure may be checked both lying and standing to uncover orthostatic hypotension. Examination of the heart, lung, and neurologic system may uncover a potential cause if these are abnormal.

Initial diagnostic tests may include an electrocardiogram (EKG) and screening blood tests like a complete blood count (CBC), electrolytes, glucose, and kidney function tests. Thyroid blood tests may be performed.

Heart rhythm disturbances may be transient and not always evident at time of the examination. On occasion, a heart monitor (Holter monitor) can be worn as an outpatient for 24 or 48 hours or for up to 30 days (event monitor). Abnormal heart rhythms and rates may be uncovered as the potential cause of syncope.

A tilt-table test can be used to uncover orthostatic hypotension and is usually done on an outpatient basis. The patient is placed at an angle on a table for 30-45 minutes (every institution has its own protocol) and blood pressure and pulse rate are measured with the patient in different positions.

Depending upon the suspicions of the health care provider, imaging may be done of the brain using computerized tomography (CT scan) or magnetic resonance imaging (MRI).

Often these tests are normal and a presumptive diagnosis is made of a non life-threatening event. However, the medical care provider may decide, in consultation with the patient, whether further testing is required and whether testing should occur in the hospital or as an outpatient. It may be reasonable in some cases to take a watchful waiting approach and not proceed with any further evaluation.