Eyes. No matter what your position, visual signals help you determine where your body is in space and how it s moving. Sensory nerves. These are in your skin, muscles and joints. Sensory nerves send messages to your brain about body movements and positions. Inner ear. The organ of balance in your inner ear is the vestibular labyrinth. It includes loop-shaped structures (semicircular canals) that contain fluid and fine, hair-like sensors that monitor the rotation of your head. Near the semicircular canals are the utricle and saccule, which contain tiny particles called otoconia (o-toe-KOE-nee-uh). These particles are attached to sensors that help detect gravity and back-and-forth motion. Good balance depends on at least two of these three sensory systems working well. For instance, closing your eyes while washing your hair in the shower doesn t mean you ll lose your balance. Signals from your inner ear and sensory nerves help keep you upright. However, if your central nervous system can t process signals from all of these locations, if the messages are contradictory, or if the sensory systems aren t functioning properly, you may experience loss of balance. Dizziness may have a number of potential causes. These may include: Vertigo Vertigo — the false sense of motion or spinning — is the most common symptom of dizziness. Sitting up or moving around may make it worse. Sometimes vertigo is severe enough to cause nausea and vomiting. Vertigo usually results from a problem with the nerves and the structures of the balance mechanism in your inner ear (vestibular system), which sense movement and changes in your head position. Abnormal rhythmic eye movements (nystagmus) almost always accompany vertigo. Causes of vertigo may include: Benign paroxysmal positional vertigo (BPPV). BPPV involves intense, brief episodes of vertigo associated with a change in the position of your head, often when you turn over in bed or sit up in the morning. It occurs when normal calcium carbonate crystals (otoconia) break loose and fall into the wrong part of the canals in your inner ear. When these particles shift, they stimulate sensors in your ear, producing an episode of vertigo. Doctors don t know what causes BPPV, but it may be a natural result of aging. Trauma to your head also may lead to BPPV. Inflammation in the inner ear. Signs and symptoms of inflammation of the inner ear (acute vestibular neuronitis or labyrinthitis) include sudden, intense vertigo that may persist for several days, with nausea and vomiting. It can be incapacitating, requiring bed rest to minimize the signs and symptoms. Fortunately, vestibular neuronitis generally subsides and clears up on its own. Recovery time may be shorter with vestibular rehabilitation exercises. Although the cause of this condition is unknown, it may be a viral infection. Meniere s disease. This disease involves the excessive buildup of fluid in your inner ear. It may affect adults at any age and is characterized by sudden episodes of vertigo lasting 30 minutes to an hour or longer. Other signs and symptoms include the feeling of fullness in your ear, buzzing or ringing in your ear (tinnitus), and fluctuating hearing loss. The cause of Meniere s disease is unknown. Vestibular migraine. People who experience a vestibular migraine are very sensitive to motion. Dizziness and vertigo caused by a vestibular migraine may be triggered by turning your head quickly, being in a crowded or confusing place, driving or riding in a vehicle, or even watching movement on TV. A vestibular migraine may cause feelings of imbalance or unsteadiness, hearing loss, muffled hearing, or ringing in your ears (tinnitus). For most people with a vestibular migraine, vertigo doesn t necessarily happen at the same time as the headache. Instead, typical migraine triggers may lead to vertigo without an actual migraine. Attacks of migrainous vertigo can last from a few minutes to several days. Acoustic neuroma. An acoustic neuroma (schwannoma) is a noncancerous (benign) growth on the acoustic nerve, which connects the inner ear to your brain. Signs and symptoms of an acoustic neuroma may include dizziness, loss of balance, hearing loss and tinnitus. Rapid changes in motion. Riding on roller coasters or in boats, cars or even airplanes may on occasion make you dizzy. Other causes. Rarely, vertigo can be a symptom of a more serious neurological problem such as a stroke, brain hemorrhage or multiple sclerosis. Feeling of faintness (presyncope) Presyncope is the medical term for feeling faint and lightheaded without losing consciousness. Sometimes nausea, pale skin and a sense of dizziness accompany a feeling of faintness. Causes of presyncope include: Drop in blood pressure (orthostatic hypotension). A dramatic drop in your systolic blood pressure — the higher number in your blood pressure reading — may result in lightheadedness or a feeling of faintness. It can occur after sitting up or standing too quickly. Inadequate output of blood from the heart. Conditions such as partially blocked arteries (atherosclerosis), disease of the heart muscle (cardiomyopathy), abnormal heart rhythm (arrhythmia) or a decrease in blood volume may cause inadequate blood flow from your heart. Loss of balance (disequilibrium) Disequilibrium is the loss of balance or the feeling of unsteadiness when you walk. Causes may include: Inner ear (vestibular) problems. Abnormalities with your inner ear can cause you to feel like you are floating, have a heavy head or are unsteady in the dark. Sensory disorders. Failing vision and nerve damage in your legs (peripheral neuropathy) are common in older adultsand may result in difficulty maintaining your balance. Joint and muscle problems. Muscle weakness and osteoarthritis — the type of arthritis that involves wear and tear of your joints — can contribute to loss of balance when it involves your weight-bearing joints. Medications. Loss of balance can be a side effect of certain medications, such as anti-seizure drugs, sedatives and tranquilizers. Lightheadedness and other kinds of dizziness Feeling lightheaded is the feeling of being spaced out or having the sensation of spinning inside your head. It can also give you the sensation that if your lightheadedness worsens, you might lose consciousness. Causes may include: Inner ear disorders. These abnormalities of your inner ear can lead to illusions of motion and make you feel like you re floating. Anxiety disorders. Certain anxiety disorders, such as panic attacks and a fear of leaving home or being in large, open spaces (agoraphobia), may cause lightheadedness. Hyperventilation. Abnormally rapid breathing that often accompanies anxiety disorders may make you feel lightheaded.