Circulation
If your brain does not get enough blood flow, you feel lightheaded. Almost everyone has experienced this on occasion when standing up quickly from a lying down position. But some people have lightheadedness from poor circulation on a frequent or chronic basis. This could be caused by arteriosclerosis or hardening of the arteries, and it is commonly seen in patients who have high blood pressure, diabetes, or high levels of blood fats (cholesterol). It is sometimes seen in patients with inadequate cardiac (heart) function or with anemia.
Certain drugs also decrease the blood flow to the brain, especially stimulants such as nicotine and caffeine. Excess salt in the diet also leads to poor circulation. Sometimes circulation is impaired by spasms in the arteries caused by emotional stress, anxiety, and tension.
If the inner ear fails to receive enough blood flow, the more specific type of dizziness occurs -- vertigo. The inner ear is very sensitive to minor alterations of blood flow and all of the causes mentioned for poor circulation to the brain also apply specifically to the inner ear.
Injury
A skull fracture that damages the inner ear produces a profound and incapacitating vertigo with nausea and hearing loss. The dizziness will last for several weeks, then slowly improve as the normal (other) side takes over.
Infection
Viruses, such as those causing the common "cold" or "flu" can attack the inner ear and its nerve connections to the brain. This can result in severe vertigo, but hearing is usually spared. However, a bacterial infection such as mastoiditis that extends into the inner ear will completely destroy both the hearing and the equilibrium function of that ear. The severity of dizziness and recovery time will be similar to that of skull fracture.
Benign Paroxysmal Positional Vertigo (BPPV)
Benign paroxysmal positional vertigo (BPPV) is a disorder that causes vertigo, dizziness, and other symptoms due to debris that has collected within a part of the inner ear. This debris, called otoconia, is made up of small crystals of calcium carbonate (sometimes referred to colloquially as "ear rocks"). With head movement, the displaced otoconia shift, sending false signals to the brain.
For additional information, resources, support, and advocacy visit The Vestibular Disorders Association (VEDA) at www.vestibular.org.