Why do I always feel faint?

Hi there

If you browse through some of the questions here you may find that there are many in relation to fainting or "near-fainting":

Should I be worried about frequent fainting episodes?

What should I do next if I'm prone to fainting and dizziness spells?

This shows how common this symptom is especially amongst the teenage age group.

Fainting has many causes though the vast majority are benign. The most likely cause is vaso-vagal, which usually occurs in young adults and has other features such as vomiting, sweating and greying of vision etc.

However it is important that you have a thorough history and clinical examination from a physician before we come to the conclusion. Some basic clinical tests may also be required. In some cases tests such as echo, Holter and tilt-table testing are done.

Treatment depends on the cause but there are measures you can take to avoid the episodes. If the episodes are fairly frequent and disrupting your quality of life the physician may recommend some medication, but again, in the vast majority, it is not required.

Hope this is of help.

Dr Nandakumar

What I notice in my clinical practice is that many of my patients who complain of feeling faint have overbreathing or hyperventilation.

We normally breathe automatically but external events or stresses can change our breathing pattern and make us feel short of breath, anxious, or ready to faint. When this happens, it’s called hyperventilation, or overbreathing.

We breathe in oxygen and breathe out carbon dioxide. In situations where there is overbreathing, we will lose too much carbon dioxide in the air that we breathe out. This causes carbon dioxide level in the blood to drop to a low level, and the blood vessel in the brain will then constrict, causing us to feel faint or giddy. The quick solution here is to learn to slow down our breathing so that the carbon dioxide level in the blood will become normal again.

Hyperventilation happens most often to people 15 to 55 years old. It can come about when you feel nervous, anxious, or stressed. It may happen more often when a woman is pregnant, but the problem usually goes away on its own after the baby is born.

Fainting happens when a person loses consciousness for a short amount of time because his brain is not getting enough oxygen. A fainting spell generally lasts from a few seconds to a few minutes. Feeling lightheaded, dizzy, weak, or nauseous sometimes happens before the person faints.

Fainting can be triggered by a number of factors, including severe pain, fear or other emotional trauma, a sudden drop in blood pressure, low blood glucose level, hyperventilation, dehydration, standing in one position for too long, sudden change of posture, physical exertion in hot temperatures, coughing too hard, straining during a bowel movement, fits, drinking alcohol, etc.

Three common types of fainting are encountered in clinical practice:

1. The first is vasovagal syncope, where the vagus nerve is involved. It can be triggered by emotional trauma, stress, the sight of blood, or prolonged standing.
2. The second is carotid sinus syncope where the carotid artery in the neck is constricted, usually after turning the head to one side or wearing a collar that is just too tight.
3. The third is situational syncope, which occurs due to straining while coughing, urinating, or passing motion.