Occasionally feeling lightheaded is not rare, especially among older
adults. Usually, it is nothing serious. The most common causes are dehydration; the side effects of medication; a sudden, temporary drop in blood pressure when standing up; or low blood sugar. Having a drink of water or orange juice and lying down for a few minutes will often resolve it.
Fainting is the temporary loss of consciousness and muscle strength. About one-third of people say they have fainted at least once. It can be frightening to witness, but a person who faints usually regains consciousness quickly.
An emotional reaction to shocking news or events, the sight of blood or an experience that creates a feeling of panic also can cause you to faint. Fainting under these circumstances is more common among young people. A young person who faints after a shocking event may not need to see a doctor.
Older adults are more likely to faint due to abnormally low blood pressure brought on by dehydration, the side effects of medication, as well as such diseases as diabetes, cancer and Parkinson’s.
A heart rate that is very fast or very slow can lead to fainting. The cause can be an abnormality in the heart, damage from heart disease or a heart attack, or certain medications.
An adult who faints for the first time after age 40 may want to see a doctor to rule out other health issues that might have caused the fainting, and you should always let your doctor know that you fainted even if your condition resolves itself or you don’t faint again.
Sometimes you may describe what you’re feeling as dizziness. If what you experience is the sensation that everything around you is spinning, that is vertigo. An inner ear infection, medications and certain diseases that affect balance and hearing can cause vertigo.
Fainting, feeling lightheaded or experiencing vertigo are not usually signs of a serious health problem. The greater danger in most cases is the risk of serious injury from a fall. However, if any of these conditions persists or begins to occur more frequently, consult your doctor.