Fainting Causes, Symptoms and Treatment
Fainting is a sudden, brief loss of consciousness. When people faint, or pass out, they usually fall down. After they are lying down, most people will recover quickly. The term doctors use for fainting is syncope. Fainting one time is usually nothing to worry about. But it is a good idea to see your doctor, because fainting could have a serious cause.
Fainting is caused by a drop in blood flow to the brain. After you lose consciousness and fall or lie down, more blood can flow to your brain so you wake up again.
The most common causes of fainting are not dangerous. In these cases, you faint because of the vasovagal reflex, which causes the heart rate to slow and the blood vessels to widen, or dilate. As a result, blood pools in the lower body and less blood goes to the brain. This reflex can be triggered by many things, including stress, pain, fear, coughing, holding your breath, and urinating.
Fainting may be the sign of a serious problem if it happens often in a short period of time. It happens without warning. (When fainting is not serious, a person often knows it is about to happen and may vomit or feel hot or queasy.) You are losing a lot of blood. This could include internal bleeding that you can't see. You feel short of breath. You have chest pain. You feel like your heart is racing or beating unevenly (palpitations).
If you know you tend to faint at certain times (such as when you get a shot or have blood drawn), it may help to sit with your head between your knees or lie down if you feel faint or have warning signs such as feeling dizzy, weak, warm, or sick to your stomach. Drink plenty of fluids so you don't get dehydrated.Stand up slowly. You may need to see a doctor if you have ongoing dizziness or fainting.