What Causes Feelings of Dizziness or Vertigo

Dizziness is a general term that can be used to describe more than one feeling. Some people will say they are dizzy when they are feeling lightheaded, "floaty" or as if they might lose consciousness. Some people say they feel dizzy because the room seems to be spinning around. (The latter condition is probably more accurately defined as vertigo.)

The sensation of feeling dizzy can be caused by multiple different conditions, but keep in mind that it would be impossible to cover all the different causes of dizziness, and what causes one person to become dizzy may not cause dizziness in others.

Body Systems Linked to Dizziness

Dizziness usually stems from a problem in one of the following body systems:

• Circulatory: dizziness can occur if not enough blood flow reaches the brain
• Neurological: the dysfunction of peripheral nerves, the brain or spinal cord can make you feel dizzy
• Inner ear: the inner ear is largely responsible for our sense of balance and equilibrium, so disorders of the inner ear can cause dizziness
• Respiratory: if we breathe too quickly or deeply, called hyperventilation, we can become dizzy or even pass out

Dizziness can occur in other ways but the cause can usually be grouped into one of the above categories.

Circulatory Causes

More specific circulatory conditions that can cause dizziness include pregnancy, dehydration or standing up too quickly (called orthostatic hypotension, a condition that is more common among the elderly and those taking certain medications).

A drop in blood pressure caused by a medication can cause dizziness, and so can internal bleeding.

Neurological Causes

Neurological conditions that can cause dizziness include chronic illnesses, such as multiple sclerosis, or head or spinal cord injuries.

Inner Ear Causes

Vertigo, which is dizziness that usually involves the sensation of spinning, can be caused by Meniere's disease, BPPV, labyrinthitis or some migraine headaches.

Respiratory Causes

The main respiratory cause of dizziness is hyperventilation due to anxiety. It can also, more rarely, be caused by an infection or other illness that leads to over-breathing.

Other Causes

Other causes of dizziness include low blood sugar, a medication you've taken or a side effect caused by combining certain medications. Motion sickness and the consumption of alcohol, narcotic pain medication or other controlled substances may also be to blame.

While the majority of the time, dizziness is temporary and self-treatable, dizziness can be caused by serious illnesses and injuries, including head injuries, strokes, seizures, bleeding into the brain (i.e., subdural hematoma) or internal hemorrhage followed by circulatory shock.

When to See a Healthcare Provider

Dizziness caused by motion sickness, by drinking alcohol or by using prescribed narcotic pain medication does not usually need to be evaluated by a healthcare provider. While not necessarily an emergency, dizziness caused by migraines should be evaluated, as should any persistent or unexplained dizziness.

If you experience dizziness after starting a new medication, stop taking the medication and call your healthcare provider as soon as possible.

Stand up slowly to avoid a sudden drop in blood pressure. Talk to your healthcare provider about the possible causes of orthostatic hypotension. This condition is not usually an emergency, but the dizziness can lead to injuries from falls and should be treated. A chronic condition called postural orthostatic tachycardia syndrome may need to be ruled out.

If you or someone you are with is hyperventilating, stay calm, take deep breaths and use other techniques to treat hyperventilation syndrome.

If you suspect low blood sugar (hypoglycemia), eat something that preferably contains both carbohydrates and protein; if you do not have a snack that contains both, carbohydrates are best. Examples of simple carbohydrates that will quickly raise blood sugar include fruit juice, candy, honey or cake icing. If you suspect that someone you are with has low blood sugar and they become unconscious, do not try to feed them because they may choke or aspirate; instead, call 911.

If you have forgotten to eat and your symptoms subside shortly after eating, you probably do not need to see a healthcare provider. If you are diabetic, however, see your healthcare provider as you may need to adjust your medication to avoid low blood sugar in the future. If you have recurrent episodes of low blood sugar for any reason, you should see a healthcare provider.

All suspected cases of low blood sugar should be treated because untreated low blood sugar can lead to serious complications, such as coma and even death. If your symptoms do not subside after eating, your dizziness is likely not the result of low blood sugar.

When to Visit the ER

Go to the emergency room if:

• You experience dizziness after a head injury or other accident
• Someone you are with loses consciousness and you are unable to wake them
• You have signs of a stroke, such as one-sided weakness or facial drooping -- postponing treatment in the case of a stroke can lead to serious long-term disability or even death
• You or someone close to you is having seizures or convulsions
• You or someone you are with has a severe headache, especially if they describe their headache as being the worst they've ever had
• You have a high fever, especially if you also have a sore or stiff neck or if you've already tried to bring the fever down using acetaminophen or other measures without success
• You have had severe diarrhea and/or vomiting and suspect dehydration
• The dizziness is accompanied by sudden hearing loss
• You have chest pain, a rapid heart rate, or difficulty breathing