What is Syncope or Fainting?

Fainting, medically known as syncope, is a condition that may need immediate medical attention. The causes of fainting may range from mild to severe conditions.

Fainting is the temporary loss of consciousness. It is usually accompanied by an interruption of awareness of oneself and the surroundings.

Syncope or fainting can happen if the patient experiences a sudden drop in blood pressure, an interruption of the brain’s blood supply, and an abrupt drop in heart rate. Due to the reduction in the brain’s blood flow, there is a shortage of oxygen supply to the cells.

The person may experience loss of consciousness and may feel lightheaded. A fainting episode may have no medical importance. However, some of these episodes may stem from a serious illness. Hence, fainting should be regarded as a medical emergency until the cause is clear and the signs and symptoms have been addressed.

Image Credit: Halfpoint / Shutterstock
Image Credit: Halfpoint / Shutterstock

Signs and Symptoms

Fainting or syncope may occur abruptly, but some patients feel an episode of syncope coming on. They may experience premonitory symptoms like feeling nauseous, lightheaded and having a feeling of fluttering in the chest or having palpitations.

The most common signs and symptoms of syncope include:

  • Blurred or tunnel vision
  • Leg heaviness
  • Confusion
  • Blacking out
  • Falling for no reason
  • Lightheadedness
  • Drowsiness
  • Dizziness
  • Feeling unsteady
  • Headaches
  • Feeling hot or warm
  • Nausea
  • Sweating
  • pallor
  • Hypotension
  • Weak pulse

Causes of Fainting

Many factors may cause syncope or fainting. Some patients may have an underlying medical condition.

The most common type of fainting is called neurally-mediated syncope or a vasovagal attack. It is usually seen in children and young people. This condition occurs because of a sudden drop in blood pressure, reducing the blood supply to the brain.

Usually, this type of syncope is triggered by a temporary dysfunction of the autonomic nervous system (ANS) which  results in a fall in blood pressure. Triggers that lead to fainting include heat, sudden pain, an unpleasant sight, sneezing, laughing, sneezing or standing up suddenly (postural tachycardia syndrome).

Fainting may also stem from fear, pain, anxiety, hunger, the use of drugs or alcohol, and intense emotional stress.

Low blood pressure may also lead to syncope. This usually happens on standing up. Also called orthostatic hypotension, the condition occurs more often in older people.

Normally, when people sit down or lie down, the pull of gravity leads to the pooling of blood in the legs. This leads to hypotension or low blood pressure. In order to counteract this situation, the nervous system normally makes the heart beat faster. Also, it narrows the blood vessels. These mechanisms help stabilize the blood pressure.

However, in orthostatic hypotension, the nervous system fails to effectively counteract the pooling of blood in the legs. As a result, when the person suddenly stands up, there will be an interruption in the brain’s blood supply, leading to fainting.

The possible causes of orthostatic hypotension include diabetes, dehydration, some medications for hypertension, and neurological conditions.

In more severe cases, heart problems may cause fainting. Also called cardiac syncope, this type is due to heart problems that lead to the reduction of the blood supply to the brain. Other causes include seizures, shock, and the use of drugs or alcohol.

What to do During a Fainting Attack

For people with a history of fainting, it’s important to recognize the signs and symptoms. For instance, feeling lightheaded and weak with a spinning sensation are warning signs of an impending syncope. If the patient experiences these signs, it’s better to lie down or sit down.

Also, place the head between the knees while sitting down. This helps blood to go to the brain. When someone faints, apply immediate response to make sure the person is safe. Call an ambulance or emergency response as soon as possible. If there are no visible injuries, encourage blood flow to the brain by raising the feet above the heart level.

Immediately loosen tight belts, collars and constrictive clothing. Keep the patient lying or sitting down for about 10 to 15 minutes.

Check for breathing. If the patient isn’t breathing, begin cardiopulmonary resuscitation (CPR). Continue CPR until the patient starts to breathe or help arrives.

Remember to regard fainting as an emergency. Always call 911 or the local emergency services if the person has fainted and isn’t breathing. Also, call 911 if the patient who fainted doesn’t regain consciousness within a few minutes, is pregnant, has diabetes, has a fall injury, is bleeding or has slurred speech. If the fainting occurred with exercise, is associated with palpitations or cardiac irregularities or have a family history of repeated fainting attacks, or of sudden death.

In some cases, patients may have convulsions, seizures, chest pain, disorientation, and paralysis of the limbs. All these need immediate medical attention.

Further Reading

Last Updated: Feb 26, 2019

Angela Betsaida B. Laguipo

Written by

Angela Betsaida B. Laguipo

Angela is a nurse by profession and a writer by heart. She graduated with honors (Cum Laude) for her Bachelor of Nursing degree at the University of Baguio, Philippines. She is currently completing her Master's Degree where she specialized in Maternal and Child Nursing and worked as a clinical instructor and educator in the School of Nursing at the University of Baguio.


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