Fainting is a sudden, generally momentary, loss of consciousness. The medical term for fainting is syncope. It is due to a lack of sufficient blood and oxygen reaching the brain. The first symptoms a person feels before fainting are dizziness and feeling hot. Moments later, the person’s vision turns black and he/she drops to the floor or slumps, if seated in a chair. Once supine(flat), generally, consciousness returns quickly as normal blood flow returns to the brain. A longer, deeper state of unconsciousness is often called a coma. It is a common problem, accounting for 3% of emergency room visits and 6% of hospital admissions.
It most often occurs when the blood pressure is too low(hypotension) and the heart does not pump a normal supply of oxygen to the brain. Other factors that influence fainting are taking in too little food and fluids, physical exercise in excess of the energy reserve of the body, and lack of sleep. Even standing up to quickly or being in too hot a room can cause fainting. Emotional stress, pain, fear, dehydration, violent coughing spells, especially in men, can also cause syncope. This type of fainting is caused by overstimulation of the vagus nerve, a nerve connected to the brain that helps control breathing and circulation. In addition, a person who stands still or erect for too long may faint. This occurs because blood pools in the leg veins, reducing the amount that is available for the heart to pump to the brain. It may also be a result from several heart, neurologic, psychiatric, metabolic, and lung disorders or a side effect of some medicines.
Some forms of syncope suggest a serious disorder, those occurring with exercise, those associated with heart palpitations or irregular heart beats, and those associated with family history of recurrent syncope or sudden death. Many times the heart will beat too slow, too rapidly, or too irregularly to pump enough blood to the brain.
The recommended treatment is to allow the person to lie flat with his or her legs elevated above the heart. As the dizziness and momentary blindness passes, the person may experience visual disturbances in the form of small bright dots. This will also pass within a few minutes. Sometimes sitting down and placing your head between your knees will help the symptoms vanish. You may feel weak afterward. It is very important, if you are a bystander, and with a person you believe is about to faint, assist them to lay down. Once they faint, they have no control and will FALL to the floor or ground. Very serious injuries can and do occur.
Sometimes fainting may be caused by a temporary drop in the blood supply to the brain caused by a TIA(transient ischemic attack) or mini-stroke. This is caused by a blocked or burst blood vessel. Seek help immediately if a fainting spell is followed by one or more of these symptoms: numbness or tingling, blurred vision, confusion, difficulty speaking, or loss of movement in arms or legs. If fainting happens frequently or if there is no obvious explanation, it is important to see a doctor at once.
If someone faints, position the person on their back with legs elevated, watch the airway and keep open, check for breathing, loosen belts, collars, or other constrictive clothing. The person should revive quickly, if not within 1 to 2 minutes, call 911 at once.