What causes dizziness?
For the body to feel balanced, the brain requires input from the inner ear, eyes, muscles and joints. Since mechanisms for maintaining balance are so complex, finding the exact cause of dizziness is often difficult and requires input from several medical specialties. Dizziness is generally not serious. However, it may be the result from problems associated with the inner ear, brain or heart. It can also be the result of medications.
General location of inner ear disorders.
Semicircular canals: Benign positional vertigo.
Vestibular nerve: vestibular neuritis and acoustic neuroma.
One of the most common causes of dizziness is inner ear disorders. These disorders include:
- Meniere’s syndrome: This syndrome is associated with the fluid balance-regulating system in the ear. Meniere’s syndrome usually only occurs in one ear, but can affect both ears. Symptoms include episodic attacks of tinnitus (ringing in the ear), ear fullness, muffled or distorted hearing, hearing loss, and severe attacks of vertigo together with nausea and vomiting. Attacks usually happen suddenly and last from 20 minutes to 24 hours. Treatment methods include changes in diet (such as following a low-salt diet and limiting the use of alcohol and caffeine), changes in medications and quitting smoking. Anti-nausea and anti-vertigo medications are other treatments. An injection of a steroid or of gentamicin (an antibiotic) directly into the ear is another treatment method. Surgery may be recommended if medical treatment is not successful.
- Benign paroxysmal positional vertigo (BPPV): This results from damage to the delicate sensory units of the balance portion of the inner ear. Symptoms of BPPV include brief spinning sensation, dizziness, a sense of imbalance, and lightheadedness brought on by changes in head and body position, such as tipping the head backward or rolling over in bed. Nausea may also occur, but hearing loss or tinnitus is not associated with this condition. Vertigo can vary in intensity from mild to severe and usually lasts only a few seconds to minutes. A series of simple, in-office head and body repositioning maneuvers can treat the condition.
- Vestibular neuritis: This condition is caused by the inflammation of the nerve cells in the inner ear that control balance. The main symptom is sudden occurrence of vertigo, which lasts from one to seven days. In most cases, this condition is caused by a viral respiratory infection like the flu. Treatments include medications to relieve the symptoms of nausea and dizziness. Significant recovery is achieved after six to eight weeks of a balance rehabilitation program. Surgery is rarely needed.
- Vestibular schwannomas: This is a benign tumor that most commonly grows on the nerve in the inner ear that controls balance. Tinnitus is usually the first symptom, after which gradual hearing loss may occur. Vertigo is usually not present. You and your physician can discuss treatment options.
Other causes of dizziness
Medications are a common source of dizziness. The medicines can include drugs to treat seizure disorders (such as carbamazepine and phenytoin), drugs to help calm or sleep (sedating drugs and antidepressants), and even drugs used to treat inner ear infections (such as gentamicin and streptomycin).
Alcohol consumption is another cause of dizziness.