Does diabetes cause dizziness?

Feeling unsteady or off-balance can be scary, especially if the sensation comes on suddenly. If you’ve been diagnosed with diabetes mellitus, dizziness may be an uncomfortably familiar experience. That’s because diabetes can cause blood sugar swings and dehydration—common causes of dizziness or lightheadedness. Untreated or poorly managed diabetes can also lead to complications such as vestibular dysfunction, which makes you feel unsteady on your feet.

If you have diabetes and are feeling dizzy, it’s important to tell your healthcare provider. A healthcare provider can help pinpoint the exact cause of your dizziness and advise you on the best treatment. 

Can diabetes cause dizziness?

There are many reasons a person with diabetes might experience dizziness. 

“The most common reason why someone with diabetes would experience dizziness would be due to low blood sugar, [which] should be considered an emergency and should be treated immediately,” says Blair Gingerich, Pharm.D., BCMTMS, a clinical care and retail pharmacist and diabetes educator in northern Indiana. She adds that dehydration and low blood pressure may also cause dizziness, though these conditions can affect anyone with or without diabetes.

If you are experiencing sudden dizziness from diabetes, the first step is to check your blood sugar levels. Short-term dizziness from high or low blood sugar can and should be treated immediately. If you are experiencing dizzy spells even when your blood sugar is stable, the cause might be linked to dehydration or a more systemic condition such as medication side effects and vestibular dysfunction, a condition diagnosed by a neurologist or an ear, nose, and throat doctor (ENT).

Low blood sugar

In many cases, dizziness is caused by a lack of sugar in the bloodstream. Low blood sugar, called hypoglycemia, is defined as a blood glucose reading below 70 milligrams per deciliter (mg/dL).

If you are wearing a continuous glucose monitor (CGM) that is not reporting low blood sugar, Dr. Gingerich says to use a finger stick and glucometer to verify the reading. “If there is a discrepancy between the glucometer and continuous glucose monitor, treatment should be based on the glucometer results,” she emphasizes.

Glucose in the blood gives your body energy. When blood sugar is low, the body must conserve energy for the most important organs and functions. This can make you feel lightheaded and dizzy. “The likelihood of experiencing dizziness tends to be higher when blood sugar levels drop suddenly,” says Amy Offutt, MD, the founder of Heart & Soul Integrative Medicine in Texas.

Other symptoms of hypoglycemia include:

• Confusion
• Fast heartbeat
• Hunger
• Irritability
• Nervousness
• Shaking or feeling jittery
• Sweating

To stop the dizziness caused by low blood sugar, the ADA recommends the “15-15 rule.” Eat 15 grams of carbohydrates, then recheck blood sugar levels in 15 minutes. If your blood sugar is still too low, eat more carbohydrates.

Here are some examples of 15 grams of carbohydrates:

• ½ cup of fruit juice
• 3 glucose tablets
• 1 tablespoon sugar

If you encounter a person with diabetes who is too tired, lightheaded, or nauseous to eat, a Glucagon Emergency Kit can provide glucose via injection. 

High blood sugar

 Excess glucose in the blood can sometimes cause dizziness. High blood sugar, called hyperglycemia, is a blood glucose reading above 125 mg/dL before eating or 180 mg/dL two hours after eating.

Insulin is a hormone that helps turn glucose into usable energy. People with diabetes have a heightened risk of high blood sugar because their bodies either do not produce insulin or cannot process it effectively. In other words, sugar can build up in the bloodstream. 

Chronic high blood sugar can lead to a dangerous condition called diabetic ketoacidosis (DKA). Dizziness is only one sign of high blood sugar. Other symptoms of high blood sugar include:

• Feeling thirsty
• Frequent urges to urinate
• Unusual hunger
• Fatigue
• Irritability
• Blurred vision

If your blood sugar is above 125 mg/dL before eating or 180 mg/dL two hours after eating, your dizziness is likely due to high blood sugar. This means you have too much glucose in your bloodstream.

If your blood sugar is high but not higher than 200 mg/dL, the American Diabetes Association (ADA) recommends exercising and cutting back on food. Brisk walking, cycling, swimming, dancing, sports, and other aerobic activities are great ways to lower blood sugar naturally. Of course, if you are experiencing dizziness, it is important to move safely without a fear of falling. You can get your blood pumping even with upper-body movements while sitting safely in a chair. 

Dehydration

“When individuals with diabetes have poorly controlled blood sugar levels, there is an increased likelihood of dehydration,” Dr. Offutt says. “This is due to the fact that elevated blood sugar, when spilled into the urine, leads to greater fluid loss.” 

Dizziness alone does not usually indicate dehydration. In most cases, someone who is dehydrated notices increased thirst. Other symptoms of dehydration include:

• Headache
• Dark yellow urine
• Dry tongue and lips
• Dry skin
• Fatigue
• Constipation

The best way to treat dehydration is to increase your fluid intake. Drink water or an electrolyte drink (avoid alcohol and caffeine, which can contribute to dehydration) and eat water-rich foods such as watermelon or celery.

Vestibular dysfunction

The vestibular system is a complicated network of internal structures and nerve connections in the inner ear that provides a sense of physical balance and coordination. People with vestibular dysfunction are more likely to lose their balance and fall.

Research shows that diabetes patients have a heightened risk of vestibular dysfunction. In other words, people with diabetes are more likely to experience balance issues than those in the general population. The exact reason is not fully understood, but it may be traced to common diabetes complications such as nerve damage and hearing impairment.

Vestibular dysfunction linked to diabetes is likely to develop over months and years. This type of dizziness is not a short-term issue like high blood glucose. Dizziness is only one sign of vestibular dysfunction. Other symptoms include:

• Loss of balance
• Vertigo
• Nausea
• Spontaneous blurred vision
• An unsteady walk

Treatment for vestibular dysfunction caused by diabetes may include balance retraining therapy, surgery, and addressing the underlying cause through diet, exercise, or medication.

Medications

“Medications can commonly induce dizziness as a side effect, and this is especially relevant for patients who often take both blood pressure and diabetes-related medications,” Dr. Offutt says. 

Blood pressure medications 

High blood pressure, or hypertension, is a very common condition in people with diabetes. High blood sugar levels can cause build-up inside the blood vessels. This gradually narrows the vessels and increases the pressure of blood pumping through them. 

Blood pressure medications that may cause dizziness as a side effect include: 

• ACE inhibitors
• Angiotensin II receptor blockers (ARBs)
• Diuretics
• Beta blockers

Diabetes medications

Treatment options for diabetes mellitus depend on whether you have Type 1 or Type 2 diabetes. 

People with Type 1 diabetes always require insulin. Gingerich says injecting too much insulin causes low blood sugar levels, which can trigger dizziness. “People with diabetes experiencing low blood sugars should report this information to their doctor as soon as possible as a dose adjustment may need to be made,” she adds.

A few Type 2 diabetes treatments that may cause dizziness as a side effect include:

• Metformin
• Sulfonylureas (Amaryl, Glucotrol, etc.)
• Alpha-glucosidase inhibitors (AGIs) 

Bottom line: Dizziness is a common drug side effect. If you’ve started to feel dizzy after starting a new medication, tell your healthcare provider right away. Depending on the severity of your dizziness, your provider may recommend stopping the medication or reducing the dose.

Diabetes-related dizziness vs. other forms of dizziness

There are many possible causes of dizziness. Diabetes-related dizziness may feel similar to other forms of dizziness, especially if a medication or vestibular dysfunction causes the sensation. 

Other signs of high or low blood sugar usually accompany blood sugar-related dizziness. For instance, you may feel lightheaded—woozy, like you’re about to pass out—or jittery and anxious. The best way to determine if your dizziness is sugar-related is to test your blood glucose levels with a glucose meter.

When to see your healthcare provider

Anyone with diabetes who is experiencing recurring or severe dizziness should consult their healthcare provider. Blood sugar management is critical to preventing diabetes-related dizziness. If you’re feeling dizzy and lightheaded regularly, it may be time to adjust your diabetes care plan through lifestyle changes and medication. Left untreated, diabetes can lead to severe, long-term complications such as neuropathy (nerve damage), heart disease, kidney problems, and vision loss.