Fainting (Syncope)

What is syncope?

Simple fainting spells, called syncope, usually occur while standing for a while or standing suddenly. These spells are usually brief in duration (less than one minute). Healthy children and adolescents may experience syncope.

Symptoms that may precede the fainting spell include:

  • Lightheadedness
  • Dizziness
  • Feeling hot
  • Paleness
  • Upset stomach
  • Palpitations
  • Tunnel or blurry vision
  • Seeing black or white spots
  • Sweating
  • Cold and clammy hands
  • There is loss of postural tone (the patient falls down), accompanied by loss of consciousness

It is unlikely that during the fainting spell there may be abnormal body movements. It is quite rare to see urinary incontinence. After fainting, there is usually no confusion and the patient is aware of his name and place. In addition, one may complain of a headache and feeling extremely tired. Some of these spells may be triggered with hyperventilation (rapid breathing) or anxiety. Fainting spells are common while standing in hot or crowded places like church.

Most patients with simple fainting spells do not drink enough water. Children need about six or eight (8 oz) glasses of water per day, while adolescents may need 8 to 13 (8 oz) glasses of water per day (2-3 liters of fluids per day). Soft drinks or caffeinated products should be avoided if at all possible.

Many of our patients that experience fainting spells do not like eating salt and may not take enough of this mineral.

What causes you to pass out?

When you stand up there is a significant amount of blood being displaced into your legs and there may not be enough blood returning back to your heart to send a sufficient amount of oxygenated blood to your brain.

This situation may get worse if you are not fully hydrated or have been standing up for a while. The heart is pumping blood on an empty tank so there is not enough oxygen being delivered to your brain and you pass out. The heart usually tries to compensate by pumping harder and faster. This may trigger certain reflexes between the heart and brain that results in a sharp drop in blood pressure and/or extreme slowing of your heart rate.

How common is this condition?

About ⅓ of healthy adolescents may experience simple fainting spells. Many of them do not keep up with adequate fluid intake and are drinking too much caffeine (which makes you urinate). This type of spells is called vasovagal syncope or neurocardiogenic syncope.

What measures should be taken to prevent fainting spells?

You should improve your fluid intake and, if you are not hypertensive, you may add extra salt to your diet. You should be careful when standing up, especially if you do it abruptly, and take an extra amount of fluid if your are going to be outdoors on a hot day or planning to exercise. Avoid drinking caffeine, alcohol, or using recreational drugs. You should avoid stressful situations, hyperventilation and anxiety.

You may need additional tests if you are passing out abruptly without any warning symptoms (such as lightheadedness and dizziness) prior to fainting or if you are passing out only while exercising or keep passing out in spite of adequate water intake. This may include a tilt table test or stress testing.

It is essential to know if there is family history of sudden death in young family members or history of Long QT syndrome, Short QT syndrome or cardiomyopathy.

What other conditions may produce syncope?

  • Dysautonomia
  • Conversion reaction
  • Dehydration
  • Trauma
  • Adverse drug reactions
  • Recreational drugs
  • Anxiety
  • Panic attacks
  • And others

Our Mission

Children's Heart Specialists, PSC is committed to provide comprehensive pediatric cardiac services to infants, children and young adults. We strive to insure the highest quality in non-invasive cardiovascular testing. Our medical staff is committed to being board certified in pediatric cardiology and adult congenital heart disease.

Our goal is to provide the highest quality of care with compassion and respect to our patients and their families.

Accredited in Echocardiography


We do not give any medical advice or recommendations about you or your child's health in this website. The medical information that appears on this website is to be used as a general guide about heart defects and symptoms. Medical advice is discussed at the time of your consultation with Dr. Villafañe.