Why do fainting occur? symptoms and causes

Why do fainting occur? symptoms and causes

Why do fainting occurs? What are the symptoms and causes in which they appear?

Fainting occurs suddenly, unconsciousness is lost, and in a few seconds or minutes because the brain does not receive enough oxygen.

There are two hemispheres of the brain: the cerebellum and the brain stem, the brain needs a blood flow to supply oxygen and glucose to the cells for the body to remain conscious, there is an area in the brain known as reticular activation or both hemispheres that are limited by blood, oxygen or glucose.

Symptoms that cause fainting:

  • Irregular heart palpitations.
  • Rapid pulse.
  • Dizziness and chills.
  • Chest pain.
  • Vision blurred and you feel lightheaded.
  • Lack of air and difficulty breathing.

Causes that produce fainting:

  • Reaction of the vagus nerve: The vagus nerve communicates the digestive system with the brain and helps transport blood flow to the brain and intestine when there is an overstimulation of the vagus nerve, it can unbalance the heart rate and decrease blood pressure arterial, reducing blood intake to the cerberus causing fainting. Anxiety, phobia and strong pain can stimulate the vagus nerve.
  • Changes in blood pressure: In some cases the heart and blood vessels do not work quickly enough to change the oxygen that the body needs, it is very common in older people, with diabetes or who do a lot of work time standing or over exertion.
  • Anemia: When red blood cell deficiency occurs there are not enough oxygen supplies reaching the brain, this causes fainting, lack of iron intake in the diet is important to maintain vitality.
  • Dehydration: The lack of water or fluid in the body can cause fainting. Some illnesses such as diabetes, diarrhea, vomiting, infections, fever, and sweating can cause dehydration.
  • State of Shock: It is a state of emergency that is generally caused by bleeding, or by some severe allergic reactions, such as a serious infection, having very low blood pressure can also cause loss of consciousness.
  • Drug use: Pharmaceuticals and drugs have a direct effect on our blood pressure as they can raise or lower it dramatically causing fainting, these can be more dangerous when mixed with alcohol.
  • Hypoglycemia: It is when due to lack of nutrition in cases of people with an advanced state of anorexia, in other cases it generally occurs in patients with diabetes due to imbalanced insulin levels.


  • When fainting symptoms begin, you should sit and squat and put your head between your knees, to help blood flow to the brain.
  • Then wait until you feel better and sit up slowly and take a deep breath and seek medical help to diagnose the cause of your problem.
  • If your fainting spells are frequent and you have heart-related problems or high blood pressure, it is best to see your doctor for close monitoring.

Leave a Reply

Your email address will not be published. Required fields are marked *