Can Low Blood Pressure Be a Sign of Diabetes?

Low blood pressure (hypotension) is marked by symptoms of dizziness and fatigue and can have many causes. While many people with diabetes have high blood pressure, diabetes can also cause low pressure from dehydration, damage to the autonomic nervous system, or medication side effects.

This article will explore whether low blood pressure can be a symptom of diabetes, and the potential causes and treatment options for low blood pressure.

What Is Low Blood Pressure?

Normal blood pressure for adults is less than 120/80 millimeters of mercury (mm Hg). There is no specific numeric cutoff for "low" blood pressure. Rather, symptoms of low blood pressure are markers of a problem. These include:

• Fatigue
• Dizziness or lightheadedness
• Vision changes
• Fainting

Low blood pressure has many causes, including:

• Anemia (not enough red blood cells)
• Bleeding
• Dehydration
• Infection
• Anaphylaxis (severe allergic reaction)
• Heart failure
• Medication side effect
• Pregnancy
• Endocrine problems, like hypothyroidism and Addison's disease

Is Low Blood Pressure a Sign of Diabetes?

More often, people with diabetes have high blood pressure. However, diabetes can also cause low blood pressure due to:

• Dehydration through fluid losses
• Autonomic neuropathy
• Medication side effects

Dehydration

When blood sugar is very high, as occurs in untreated diabetes, it causes sugar to leak into the urine. The sugar in the urine also drags water with it, which can result in dehydration. When significant, dehydration results in low blood pressure.

A serious condition called diabetic ketoacidosis (DKA) leads to significant dehydration with high levels of sugar in the blood and urine. Symptoms of DKA include fatigue, abdominal pain, nausea, frequent urination, and dry mouth. DKA is sometimes the first sign of type 1 diabetes in someone who has not been diagnosed.

Hyperosmolar hypoglycemic state is a similar condition that occurs more often in people with type 2 diabetes. It causes severe dehydration.

Autonomic Neuropathy

People with longstanding diabetes can develop damage to the nerves from chronically high blood sugar levels. This can result in autonomic neuropathy, a condition that can cause episodes of low blood pressure. Low blood pressure can occur with standing (orthostatic hypotension) or after eating (postprandial hypotension) and cause symptoms like dizziness, lightheadedness, and even falls.

In autonomic neuropathy, damaged nerves don't appropriately transmit signals to blood vessels to constrict to appropriately maintain blood pressure levels. This can lead to abrupt drops in blood pressure, particularly when standing.

Medication Side Effect

Some medications used to treat diabetes can have low blood pressure as a side effect. Sodium-glucose cotransporter 2 (SGLT2) inhibitors work by increasing the amount of blood sugar lost in the urine, which can contribute to low blood pressure. Examples of SGLT-2 inhibitors include:

• Brenzavvy (bexagliflozin)
• Canagliflozin (Invokana)
• Dapagliflozin (Farxiga)
• Empagliflozin (Jardiance)

If you take any of these medications, talk with your healthcare provider about possible side effects.

Treatment and Management of Low Blood Pressure

Determining the cause of low blood pressure is the first step in managing it. For example, if the cause is dehydration from excess fluid losses, getting better control of your blood sugar and staying well-hydrated can help.

For people who get low blood pressure after a meal (post-prandial hypotension) or after sitting or standing (orthostatic hypotension), the following may help:

• Avoiding large meals and eating more frequent smaller meals
• Drinking plenty of fluids, and avoiding beverages with a high sugar content
• Avoiding standing for long periods (if it is necessary to stand, pump your calf muscles to promote blood flow)
• Avoiding alcohol
• Increasing salt intake
• Standing up slowly
• Using compression stockings or socks
  

If you feel faint or experience dizziness, it's always safest to sit or lie down. This will help to avoid injury in the event of falls or fainting. In autonomic neuropathy, other treatments might be required, such as medications that can help raise blood pressure (e.g, midodrine and fludrocortisone).

When to See a Healthcare Provider

If you have signs of low blood pressure make an appointment with your healthcare provider to find out what is causing it. Low blood pressure can be dangerous. You should seek emergency medical attention if you experience the following symptoms:

• Irregular heartbeat
  
• Difficulty breathing
• Chest pain
• Fainting
• Fever higher than 101 degrees Fahrenheit
• Black or maroon stool

Summary

Diabetes is more often linked with high blood pressure, but it can also cause low blood pressure. There's no cutoff number for blood pressure to be considered low; rather, low blood pressure is of concern when it causes symptoms. Diabetes can be linked to low blood pressure that's caused by dehydration, autonomic neuropathy, and medication side effects. Talk with your healthcare provider about any symptoms you have. They can find out the cause and come up with a treatment plan for you.

A Word from Verywell

Episodes of low blood pressure can be frightening and affect your daily life. If you find yourself with frequent episodes of dizziness and vision changes that are linked to low blood pressure, talk to your provider about steps you can take to minimize your symptoms and keep your blood pressure at a normal level.