Fatigue is a common symptom of diabetes and can result from high blood sugar levels and other symptoms and complications of the condition. Some lifestyle changes can help a person manage diabetes fatigue.

Fatigue is different from being tired. When a person is merely tired, they usually feel better with rest. When a person has persistent fatigue, rest may not relieve their feelings of exhaustion and lethargy.

According to the American Diabetes Association, research shows that 61 percent of people with newly diagnosed type 2 diabetes report fatigue as a symptom. Also, the same study found that fatigue is the second most common symptom in this group.

In this article, we look at the reasons why diabetes can cause fatigue and how to manage fatigue. We also cover other possible cause of fatigue and when to see a doctor.

Why does diabetes cause fatigue?

Tired woman holding head because of diabetes fatigue
Fatigue is a common symptom of diabetes.

There are many reasons why diabetes can cause fatigue, including:

  • changes in blood sugar levels
  • other diabetes symptoms
  • complications of diabetes
  • mental and emotional issues that result from diabetes
  • being overweight

We discuss each of these possible causes of fatigue below.

Changes in blood sugar levels

Diabetes affects the way the body regulates and uses blood sugar.

When a person eats, the body breaks down the food into simple sugars. In people with diabetes, these sugars can accumulate in the blood instead of moving into the cells. The cells need the sugar to provide energy.

When the body’s cells are not getting enough sugar, it can cause symptoms, including fatigue and weakness. Diabetes medications, such as insulin or metformin, help more of this sugar to move into the cells and prevent sugar from accumulating in the blood.

A potential side effect of diabetes medications is low blood sugar or hypoglycemia.

Low blood sugar can also cause fatigue, especially in people who do not get enough warning that their blood sugars levels are about to drop. A person can also feel fatigued after treatment of low blood sugar.

Other diabetes symptoms

Other symptoms of diabetes can also contribute to a person having to face excess fatigue. These symptoms can include:

  • frequent urination
  • excessive thirst
  • extreme hunger despite eating
  • unexplained weight loss
  • blurred vision

While not all of those symptoms can account for feelings of fatigue, many of them may contribute to an overall sense of being unwell. This unwell feeling may take a mental and physical toll on a person that can lead them to experience fatigue.

Also, some of the symptoms of diabetes may disrupt a person’s sleep. For example, with diabetes, they may find themselves waking up several times a night to use the bathroom or get a drink.

Similarly, discomfort in the extremities may make it difficult for a person with diabetes to fall asleep and stay asleep.

These sleep disruptions can cause a person to feel increasing fatigue.

Diabetes complications

Heart disease is a potential complication of diabetes.
Managing diabetes can help prevent complications, such as heart disease.

People with diabetes can develop complications that can also contribute to feelings of fatigue. These complications typically develop when a person’s blood sugar levels remain too high and can include:

These complications, as well as the medications a person uses to treat them, may contribute to feelings of fatigue in people with diabetes.

Mental and emotional health

Living with diabetes can often impact a person’s mental and emotional health. According to 2016 research, people with diabetes may be around two to three times more likely to experience depression than people without the condition.

Depression can also adversely affect a person’s blood sugar control and lead to fatigue.

In fact, many of the symptoms of depression relate directly to fatigue, including:

  • changes in sleeping patterns
  • waking too early or being unable to fall back to sleep
  • loss of energy

Aside from depression, many people with diabetes may also experience increased anxiety related to their health. Similarly to depression, anxiety can also cause increased feelings of fatigue due to disrupted sleep.

Being overweight

Many people with diabetes, especially those with type 2 diabetes, are overweight or obese, which can also contribute to fatigue. Reasons for the association between being overweight and fatigue may include:

  • lifestyle choices that may lead to weight gains, such as lack of exercise or an unhealthful diet
  • the increased energy needed to move a person’s body
  • sleep disruption from complications of being overweight, such as sleep apnea

How to manage diabetes fatigue

Lifestyle changes can help a person manage both diabetes and symptoms of fatigue. Helpful lifestyle changes may include:

  • maintaining a healthful weight or losing weight if necessary
  • getting regularly exercise
  • eating a healthful diet
  • practicing good sleep hygiene, including setting regular bedtimes, getting 7 to 9 hours sleep, and unwinding before bed
  • managing and limiting stress
  • seeking support from friends and family

To reduce fatigue, it is also essential for a person to properly manage their diabetes and any coexisting conditions. This may include:

  • regularly monitoring blood sugar levels
  • following a diet that limits refined carbohydrates and simple sugars
  • taking all diabetes medications, as a doctor instructs
  • getting correct treatment for any related conditions, such as cardiovascular disease, kidney disease, and depression

Other possible causes of fatigue

Person taking medication from blister pack
Some types of medication may cause fatigue as a side effect.

There may be other reasons a person with diabetes experiences fatigue that is not directly related to their condition. These might include:

  • acute illness
  • unrelated stress
  • anemia
  • arthritis or other chronic conditions that cause inflammation
  • hormonal imbalances
  • sleep apnea
  • side effects of medications

When to see a doctor

A person with diabetes should see their doctor regularly to monitor and manage their diabetes. Also, they may wish to speak to a doctor for fatigue that interferes with daily life or is a new or worsening symptom, as this could be a sign of a potential complication or side effect of medication.

People should seek medical attention for fatigue that occurs alongside other symptoms, such as fever, chills, or malaise, as this could indicate an infection.


People with diabetes commonly experience persistent fatigue. Causes of fatigue can include high or low blood sugar levels, depression, being overweight, and coinciding medical conditions.

While fatigue can interfere with a person’s daily life, controlling blood sugar levels and lifestyle changes can improve energy levels and reduce tiredness and lethargy.