7 causes of dizzy spells — from dehydration to a pre-stroke warning sign

• One common cause of dizzy spells is anemia, which happens when your body needs more red blood cells.
• Dizziness can also happen if you are dehydrated, which also causes confusion and dry mouth.

You may be going about your day normally when a sudden dizzy spell makes you feel as though you are off-balance, unsteady, or spinning.

It can occur for any number of reasons, like dehydration, inner ear problems, or nutritional deficiencies.

A dizzy spell may happen by itself, but it can also be accompanied by other symptoms. It's best to see a healthcare provider to identify and treat the cause.

Here are seven potential causes of dizzy spells and how to treat them.

1. Anemia

Anemia occurs when you don't have enough functioning red blood cells to carry oxygen throughout your body.

The lack of oxygen to the brain may cause dizziness, says Dr. Sindhu Aderson, medical director of the Northwestern Medicine Immediate Care, because the brain requires a steady supply of oxygen-rich blood to function properly.

Other symptoms of anemia include:

• Shortness of breath
• Cold hands and feet
• Worsening dizziness when shifting positions (sitting to standing, etc.)
• Pale or yellowish skin
• Weakness
• Headaches

How to treat it: Your healthcare provider will treat anemia based on the underlying cause. You may need iron supplements, dietary supplements, blood transfusions, medications, or bone marrow transplantation, depending on your condition.

2. Dehydration

You are dehydrated when your body doesn't have sufficient water and other fluids to function normally, says Aderson. Not having enough fluids may keep the brain from getting enough blood. As a result, you might experience a dizzy spell.

Watch out for the other signs of dehydration, such as:

• Confusion
• Fatigue
• Worsening symptoms
• Worsening dizziness when shifting positions
• Dry mouth
• Weakness
• Heat intolerance

How to treat it: If your dizziness was caused by dehydration, rehydrating should resolve it, Aderson says.

Drinking about eight glasses of water per day is reasonable, but you may need more fluids depending on factors like age, weight, and level of physical activity.

3. Benign paroxysmal positional vertigo (BPPV)

BPPV occurs when gravity- and motion-sensing particles in the inner ear become dislodged and settle in the wrong position.

"In their new location, they stimulate the brain and inner ear incorrectly and cause short but intense episodes of dizziness during certain head movements," says Dr. Scott Shapiro, assistant professor in the Department of Otolaryngology - Head and Neck Surgery at the Rutgers Robert Wood Johnson Medical School.

The condition may also cause the following symptoms:

• Nausea
• Vomiting
• Unsteadiness
• Abnormal rhythmic eye movements

How to treat it: BPPV may go away on its own in a few weeks or months, so it is rarely serious other than when it increases the risk of falls.

You can perform specific exercises or maneuvers to shift the inner ear particles back to their normal position, Shapiro says. One of these is the Epley maneuver where you lie on your back and perform a series of head movements to relieve symptoms.

4. Orthostatic hypotension

Orthostatic hypotension is a drop in blood pressure that happens when going from sitting or lying down to a standing position.

"With the drop in pressure, not enough blood reaches the brain temporarily, which manifests as dizziness or lightheadedness when standing and usually lasts a few seconds, though sometimes longer," Shapiro says.

Other symptoms include:

• Confusion
• Weakness
• Blurry vision
• Fainting

How to treat it: The treatment for orthostatic hypotension is directed at the underlying cause, Aderson says. Conditions like low heart rate, low blood sugar, and Parkinson's disease may all cause orthostatic hypotension.

5. Transient ischemic attack (TIA)

A TIA is a brief episode where you experience symptoms similar to a stroke.

Although the episode typically lasts less than an hour, you still need urgent medical attention because it usually happens hours or days before a stroke.

It occurs when the blood supply to a certain part of the brain is temporarily blocked, which may cause dizziness, Aderson says.

Symptoms tend to happen suddenly, including:

• Numbness
• Trouble speaking
• Confusion
• Difficulty walking
• Vision loss or change

How to treat it: If you suspect you are experiencing a TIA, you need to call 911 immediately even if symptoms resolve.

The goal of the treatment of TIA is to prevent a stroke. Healthcare providers may prescribe anti-platelet drugs or anticoagulants, recommend surgery, or perform angioplasty.

"Specialized vestibular or balance physical therapy is often a crucial part of treatment if patients suffer from dizziness or imbalance due to a stroke or TIA," Shapiro says.

6. Ménière's disease

Ménière's disease is a chronic condition that affects the inner ear, which contains fluid and sensory hair cells that helps the body maintain balance.

Fluid and pressure abnormalities in the inner ear cause inflammation that may result in various symptoms, Shapiro says, which include:

• Vertigo, the severe dizziness where you feel like you're spinning even when you're not
• Hearing loss
• "Drop attacks" where you lose your balance and fall or feel like you are suddenly being pushed to the ground
• Nausea and vomiting
• Ringing, roaring, or buzzing sound in your ear

These symptoms typically occur together in an episode that may last two to three hours.

How to treat it: There is no cure for Meniere's disease, but medications, therapies, middle ear injections, and surgery are some of the treatment options to control its symptoms.

7. Low vitamin B12 levels

Your body needs vitamin B12 to maintain the health of your blood and nerve cells. If you don't have enough vitamin B12, your nervous system may get damaged, which may cause dizziness.

According to Shapiro, a deficiency in vitamin B12 can lead to dizziness that is often accompanied by other symptoms of an unhealthy nervous system, such as:

• Headaches
• Numbness
• Tingling
• Lightheadedness
• Confusion

Vitamin B-12 deficiency may also cause anemia, another potential cause of dizziness.

How to treat it: If your vitamin B12 levels are too low, a healthcare provider will recommend the most appropriate treatment for you, which may come in the form of B12 medications, supplements, injections, or nasal sprays.

Insider's takeaways

If you often have dizzy spells, you are advised to see a healthcare provider. Disclose all the symptoms you experience to help them identify and treat the underlying cause of dizziness.

Treatment ranges from dietary supplements and medications to middle ear injections and bone marrow transplantation.