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Fainting-Causes, Symptoms and Prevention

A faint is characterized by suddenly feeling weak and unsteady, before passing out for a short period of time, usually just for a few seconds. It can happen when you are sitting down, standing up, or when you get up too quickly, and is caused by a momentary shortage of oxygen to the brain. Fainting is your body's way of getting you to lie down, so that oxygen-carrying blood can quickly get back to your brain

When a person faints, the loss of consciousness is brief. The person will wake up as soon as normal blood flow is restored to the brain. Blood flow is usually restored by lying flat for a short time. This position puts the head on the same level as the heart so that blood flows more easily to the brain.

A fainting episode may be completely harmless and of no significance, but it can be a symptom of a serious underlying disorder. No matter how trivial it seems, a fainting episode should be treated as a medical emergency until the cause is determined.

Stressful situations, pain and excitement can all cause fainting. They cause feelings of strong emotion, distress or shock, which puts physical and mental strain on the body. Stressful situations may be anything from receiving an injection, to feeling panicky in a hot and overcrowded room. Fainting can also occur when you feel very nervous, or after witnessing a shocking or unexpected event.

Symptoms of fainting

Just before you lose consciousness, you may experience the following symptoms:

Yawning;

A sudden clammy sweat;

Nausea;

Fast, deep breathing;

Confusion;

Blurred vision or 'spots' in front of the eyes; and

Ringing in the ears.

This is followed by loss of strength and loss of consciousness. It takes only a few seconds for this sequence to run, and there may be very little warning before a person collapses.

By collapsing to the ground, your head and heart are on the same level. This means your heart does not have to work as hard to push blood up to the brain, and you should return to consciousness after a few seconds. It is common to feel confused and weak for 20-30 minutes after fainting.

If you already feel unwell, you may be more likely to faint. People who are otherwise healthy can also faint suddenly and unexpectedly.

Causes of fainting

Fainting may occur while you are urinating, having a bowel movement (especially if straining), coughing strenuously, or when you have been standing in one place too long. Fainting can also be related to fear, severe pain, or emotional distress.

A sudden drop in blood pressure can cause you to faint. This may happen if you are bleeding or severely dehydrated. It can also happen if you stand up very suddenly from a lying position.

A faint occurs when insufficient amounts of oxygen are reaching the brain. There may be many reasons for this.

The most common is a vasovagal attack, where overstimulation of a major nerve (the vagus) slows the heart rate and lowers blood pressure. This overstimulation may be caused by intense stress, fear, pain or anything that suddenly increases pressure inside the body, such as blowing a trumpet.

Fainting may also result from low blood pressure, or hypotension, often when someone stands up suddenly or is dehydrated and low in body fluids. More rarely, fainting is due to abnormalities of the heartbeat.

Other reasons you may faint include hyperventilation, use of alcohol or drugs, or low blood sugar.

Diagnosis of fainting

Diagnosis of fainting starts with a medical history and physical exam. This may be all that is needed to make the diagnosis and determine the cause. The healthcare provider may order one or more of the following tests:

Blood tests, including a blood glucose test

A cardiac catheterization, which shows blood flow through the heart

A cerebral angiogram, which shows the blood flow to the brain

A chest X-ray

A cranial CT scan, which can show abnormalities in the brain

An electrocardiogram, or ECG, which shows the electrical activity of the heart

A tilt table test, which detects drops in blood pressure when a person stands up

General Home Care

If you have low blood sugar, eat 5 or 6 small meals a day. Make sure they are high in protein (meat, chicken, fish, cheese) and complex carbohydrates (grains and cereals). Avoid sugar and simple carbohydrates (candy and other sweets).

If you are with someone who faints, there are a number of things you should do. If he is sitting, carefully support him in a bent position, with his head between his knees; if he is lying down, raise his feet higher than his head. Turn his head to the side, so that his tongue does not accidentally block his breathing and so that any vomit will not cause choking. You may try reviving him by putting a cold, wet washcloth on his face or neck. If he feels cold to the touch, cover him with a blanket.

Checking the person's airway and breathing.

Loosening tight clothing around the neck.

If vomiting has occurred, turning the person onto one side to prevent choking

Elevating the feet above the level of the heart.

Treatment of fainting

Once he regains consciousness, do not allow him to get up immediately. Elevate the person's feet. If the person was lying down, after several minutes ask him to sit up. Ask him to sit for several minutes before standing. Then be prepared to support him in case he faints again when he stands.

If you suffer from episodes of fainting, the type of treatment your doctor offers will depend on the cause of your fainting spells and how often you experience them.

Infrequent non-heart related fainting may be not be treated.

You may be given certain medications to manage the underlying problem, or if you have an arrhythmia you may require a pacemaker.

In certain instances, you may be asked to wear certain types of support hose that help keep your blood pressure in balance or to increase your salt intake, which increases your blood volume.

Prevention of fainting

To help prevent fainting, people who have documented vasovagal attacks should be on a high-salt diet and drink plenty of fluids to avoid dehydration and maintain blood volume. They should watch for the warning signs of fainting -- dizziness, nausea, and sweaty palms -- and sit or lie down if they feel the warning signs

People who feel faint, or who pass out for a few seconds, should lie down or sit with their head between their legs for 20-30 minutes, or until they have fully recovered. Standing up again too soon causes dizziness and may trigger another faint.

If a person is feeling faint, unconsciousness may be prevented by sitting with the head between the knees or lying flat with the legs raised.

Call The Doctor

See your doctor if your fainting is associated with any of these features:

Irregular heart beat

Chest pain

Shortness of breath

Sudden onset (no warning signs)

Blurred vision

Confusion

Trouble talking

Fainting when you turn your head

Fainting more than once in a month

Fell from a height, especially if injured or bleeding.

Does not regain consciousness quickly (within a couple of minutes).

Is pregnant or over 50 years old.

Has diabetes

Has convulsions, tongue trauma, or loss of bowel control.