Lightheadedness

Light-headedness is a common and often unpleasant sensation of dizziness and/or feeling that one may be about to faint, which may be transient, recurrent, or occasionally chronic. In some cases, the individual may feel as though his or her head is weightless. The individual may also feel as though the room is "spinning" or moving (vertigo). Most causes of dizziness are not serious and either cure themselves quickly or are easily treated.

Keeping a sense of balance requires the brain to process a variety of information from the eyes, the nervous system, and the inner ears. However, if the brain can't process signals from all of these locations, if the messages are contradictory, or if the sensory systems aren't functioning properly, an individual may experience dizziness and loss of balance.

Causes
Light-headedness can be simply (and most commonly) an indication of a temporary shortage of blood or oxygen to the brain due to a drop in blood pressure, rapid dehydration from vomiting, diarrhea, or fever, or from playing a wind instrument. Other causes are low blood sugar, hyperventilation, panic attacks, and anaemia. It can also be a symptom of many other conditions, some of them serious, such as heart problems (including abnormal heart rhythm or heart attack), respiratory problems such as pulmonary embolism, and also stroke, bleeding, and shock. If any of these serious disorders is present, the individual will usually have additional symptoms such as chest pain, a feeling of a racing heart, loss of speech or change in vision.

Many people, especially as they age, experience light-headedness if they arise too quickly from a lying or seated position. Light-headedness often accompanies the flu, hypoglycaemia, common cold, or allergies. Dizziness could be provoked by the use of antihistamine drugs, like Xyzal (Levocetirizine) or by some antibiotics or SSRIs. Nicotine of tobacco products can cause lightheadedness for inexperienced users.

Treatment
Treatment for light-headedness depends on the cause or underlying problem. Treatment may include drinking plenty of water or other fluids (unless the light-headedness is the result of water intoxication in which case drinking water is quite dangerous). If a sufferer is unable to keep fluids down from nausea or vomiting, they may need intravenous fluid. Sufferers should try eating something sugary and lying down or sitting and reducing the elevation of the head relative to the body (for example, by positioning the head between the knees).

Other simple remedies include avoiding sudden changes in posture when sitting or lying and avoiding bright lights.

Several essential electrolytes are excreted when the body perspires. When people are out in unusual heat for a long time, sweating can cause a lack of some of these electrolytes, which in turn can cause lightheadedness.