Dizziness

Dizziness has many possible causes. These include conditions that affect the inner ear, motion sickness and medicine side effects. Very rarely, dizziness may be caused by a condition such as poor circulation, infection or injury.

The way dizziness makes you feel and the things that trigger it for you provide clues about possible causes. How long the dizziness lasts and any other symptoms that you have also can help healthcare professionals pinpoint the cause.

Inner ear conditions that cause dizziness due to vertigo

Your sense of balance depends on the combined input from the various parts of your sensory system. These include your:

• Eyes, which help you figure out where your body is in space and how it’s moving.
• Sensory nerves, which send messages to your brain about body movements and positions.
• Inner ear, which houses sensors that help detect gravity and back-and-forth motion.

Vertigo is the sense that your surroundings are spinning or moving. With inner ear conditions, your brain receives signals from the inner ear that don’t match what your eyes and sensory nerves are receiving. Vertigo is what results as your brain works to sort out the confusion.

• Benign paroxysmal positional vertigo (BPPV). This condition causes an intense and brief sense that you’re spinning or moving. These bouts are triggered by a rapid change in head movement. These changes in head movement can happen when you turn over in bed, sit up or get hit in the head. BPPV is the most common cause of vertigo.
• Viral infection. A viral infection called vestibular neuritis can cause intense, constant vertigo. It’s an infection of the main nerve that leads from the inner ear to the brain, called the vestibular nerve. If you also have sudden hearing loss, you may have a condition called labyrinthitis. It can be caused by a virus, and it affects the nerve in the brain that controls balance and hearing.
• Migraine. People who get migraines may have bouts of vertigo or other types of dizziness even when they’re not having bad headaches. Such vertigo bouts can last minutes to hours. They may be linked with headache as well as with being sensitive to light and noise.
• Meniere’s disease. This rare disease involves the buildup of too much fluid in the inner ear. It causes sudden bouts of vertigo that can last for hours. It also can cause hearing loss that may come and go, ringing in the ear, and the feeling of a plugged ear.

Circulation problems that cause dizziness

You may feel dizzy, faint or off balance if too little blood reaches your brain. Causes include:

• Drop in blood pressure. A form of low blood pressure called orthostatic hypotension may make you briefly feel faint or dizzy. This type of low blood pressure happens after sitting up or standing too quickly.
• Poor blood flow. Conditions such as cardiomyopathy, heart attack, irregular heartbeat and transient ischemic attack could cause dizziness. Also, a drop in the total amount of blood flowing through the body may cause the brain or inner ear not to receive enough blood.

Other causes of dizziness

Dizziness may result from conditions or circumstances like these:

• Nervous system conditions. Some conditions that affect the brain, spinal cord or parts of the body controlled by nerves can lead to a loss of balance that becomes worse over time. These conditions include Parkinson’s disease and multiple sclerosis.
• Medicines. Dizziness can be a side effect of certain medicines. These include anti-seizure medicines, antidepressants, sedatives and tranquilizers. Medicines that lower blood pressure may cause faintness if they lower blood pressure too much.
• Anxiety disorders. Certain types of anxiety may cause lightheadedness or a woozy feeling often referred to as dizziness. These include panic attacks and a fear of leaving home or being in large, open spaces. This fear is called agoraphobia.
• Anemia. There are several conditions that result in having too few healthy red blood cells, also called anemia. Other symptoms that may happen along with dizziness if you have anemia include fatigue, weakness and pale skin.
• Low blood sugar. Another name for this is hypoglycemia. This condition usually happens in people with diabetes who use insulin to help lower blood sugar. Dizziness may happen along with sweating and anxiety. If you have missed a meal and are hungry, that may cause unpleasant symptoms, but this is not considered hypoglycemia.
• Carbon monoxide poisoning. Symptoms of carbon monoxide poisoning are often described as flu-like. The symptoms include headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion.
• Overheating or not enough hydration. If you’re active in hot weather or if you don’t drink enough fluids, you may feel dizzy from overheating or from not being hydrated enough. The risk is even higher if you take certain heart medicines.