There are many reasons for fainting, which can be due to certain habits, climatic and weather conditions and health issues. Here let us look at some of the more common reasons for fainting.

Dehydration

When you tend to lose too much fluid from your body or when you don’t drink enough, you will suffer from dehydration. The result is that your blood pressure will drop and when the nervous system cannot control the condition well, you will finally faint. It is therefore essential to get enough fluids to drink, especially when it is hot outside.

 Irregular heartbeat

Medically the condition of irregular heartbeat is called arrhythmia. This sort of irregular heartbeat will sometimes not allow enough of blood flow to your brain and thus cause you to faint. It might be the sign of a serious heart problem, and you should consult a doctor immediately.

Breath-holding

This is called cyanotic breath-holding, which is prevalent in kids int he age group of 6 months to 5 years. The children have a tendency to cry so hard that it cuts oxygen and triggers an automatic response of fainting. They turn blue, lose consciousness for few minutes and get groggy afterwards. This is a reflex action, and the children do not do it on purpose.

There is another kind of breath holding called the pallid breath-holding. This is also seen in kids, where the child when frightened or in severe pain will open its mouth, turn pale, lose consciousness and faint. It is not the injury that causes it but the shock of it that stimulates fainting.

Hypoglycemia

Hypoglycemia is more simple terms means – low blood sugar level. When the body gets low in its sugar level, it causes dizziness, shakiness, confusion and feeling of tiredness. The person may also have blurred vision. If the problem is not fixed with some immediate remedy like a candy, fruit juice or drink the person will pass out. This may need hospitalisation and medication to regain normal sugar levels.

Hypoglycemia

Due to high blood sugar levels certain nerves in the body that control high blood pressure may get damaged in diabetics. The result is that the person will have a sudden surge in blood pressure, which will cause fainting.

Medications

Some medicines used to control high blood pressure and certain antidepressants will affect the way the heart and blood vessels are functioning. These medicines will make the blood pressure drop when a person stands up and cause fainting. Insulin used in treating diabetes can also cause hypoglycaemia leading to fainting.

Seizures

A sudden change in the brain’s electrical activity is called as seizure. The symptoms include eyes rolling back, jerky movements of the body and finally even fainting. This fainting maybe for more than few minutes at a time.

Heart problems

If you have heart problems especially damage to the heart muscles, blocked or narrowed coronary arteries etc. there won’t be enough of oxygen-rich blood that reaches the brain. This causes a person to pass out or faint. This is called cardiac syncope.

Effect of Shock

The human body can react to the sight of blood, sudden intense emotion, fear of injury, or anything that can suddenly jar your senses. This is called as vasovagal syncope or shock and causes fainting.

Hyperventilation

Sometimes out of fear, you feel that you are suddenly not able to breathe correctly. You start to breath more quickly to get more air. Meanwhile the brain vessels around your brain shrink suddenly and you feel lightheaded. This can also cause you to faint.

Some other reasons like continuous and sudden cough will not allow blood to get enough oxygen, excessive alcohol expanding your blood vessels causing drop in blood pressure, and even simple things like wearing a tight necktie that pressurises the carotid artery in the neck can cause you to faint.