The brain has several parts, including the two hemispheres, cerebellum, and brain stem. The brain requires blood flow to provide oxygen and glucose into the cells. For your body to remain conscious, an area known as the reticular activating system located in the brainstem should live, and at least one hemisphere of the brain must function. Fainting occurs when the reticular activating system or both hemispheres of the brain is deprived of blood, oxygen, or glucose.
Fainting mostly triggered by the vagus nerve that connects the digestive system to the brain and play a role managing the flow of blood to the brain and gut. Overstimulation vagus nerve slows the heart rate and lowering blood pressure, thereby reducing the intake of blood to the brain, causing fainting. Stress, fear, anxiety, panic, and strong pain can stimulate the vagus nerve.1. Reaction of the vagus nerve
Before fainting, you usually feel dizzy, dizzy, the room such as spinning, nausea and cold sweats. You also may experience blurred vision or hearing whistling. If you feel like going to faint, lie down. If you are unable to lie down, sit and squat by putting your head between your knees. This helps blood flow to your brain. Wait until you feel better before trying to stand. When you stand up, do it slowly.
2. Changes in blood pressure
Changes in blood pressure can cause you to faint. Sometimes, the heart and blood vessels do not react fast enough when you change your body's oxygen needs. It is very common in the elderly and in people who have certain health conditions, like diabetes. Fainting may occur if you stand too long or work harder than ability.
3. Anemia
Anemia (deficiency of red blood cells) can cause fainting because not enough red blood cells to supply oxygen to the brain. Anemia can be caused by lack of iron intake, disease or bleeding (eg, excessive menstruation).
4. Dehydration
Lack of fluid in the body (dehydration) also can cause fainting. Dehydration can be caused by vomiting, diarrhea, fever, sweating, burns or less drinking. Some diseases like diabetes can also cause dehydration due to too frequent urination. Vomiting and diarrhea, in particular, also stimulates the vagus nerve so that the double effect.
5. Shock
Shock is a condition characterized by low blood pressure which can lead to loss of consciousness. Shock is a dangerous state of emergency that usually originates from bleeding, but also can come from severe allergies (anaphylaxis) or a severe infection. Victims usually looks confused shock, before losing consciousness when his condition worsened.
6. Drug
Drugs that are intended to control the action of high blood pressure can be too much to lower blood pressure causing fainting. Alcohol, cocaine and marijuana also can cause fainting. Talk with your doctor if you think your fainting may be related to medications you use.
7. Hypoglycemia
Lack of blood sugar (hypoglycemia) can make you faint. Hypoglycemia is not only caused by diabetes, but also because you do not eat for a long time.
