How a Cold or the Flu Affects Blood Sugar Levels

Individuals with diabetes are more vulnerable to health complications if they come down with the flu or a cold. According to the Center for Disease Control and Prevention, individuals diagnosed with diabetes are 3 times more likely to be hospitalized for complications due to the flu than those who don’t have diabetes.

managing blood glucose levels

For this reason, diabetes patients should take extra precautions to protect themselves from colds or the flu. Any kind of physiological stress on the body will raise blood glucose levels and may make it more difficult to manage diabetes.

The Body’s Response to Illness

Illness produces a stress response in the body and increases levels of cortisol, adrenaline, growth hormone, and glucagon. When the body responds to the stress of illness, insulin levels fall and the body releases more glucose to ensure that it is prepared with sufficient energy to react. If blood sugar levels are too low, the body won’t have enough energy to react to the stress response.

As stress hormones increase, the body becomes less responsive to insulin, resulting in excess glucose in the blood stream. When the blood is loaded with glucose, white blood cells (which help fight infections) are unable to reach the intruding bacteria or virus. A slow immune response keeps the body from recovering efficiently and may lead to further complications.

Complications due to flu or cold infection


Individuals who have type 1 diabetes have a high risk of developing ketoacidosis (a buildup of ketones in the body which the kidneys are unable to remove). These individuals must test for this condition if blood glucose levels rise too high, as this can become life-threatening if not monitored properly.


Diabetes increases vulnerability to respiratory infections, which may lead to pneumonia. Pneumonia can turn into a very serious illness, and may cause even more serious complications.

Managing blood glucose levels while sick

It’s especially important to continue to monitor your blood glucose levels on a regular basis and administer insulin when needed. Using a touchscreen insulin pump with continuous blood glucose monitoring can help individuals more easily manage blood glucose levels compared to injections.

Being ill may leave you with less energy and less desire to continue to practice good diabetes management. It is important to continue to eat meals regularly, as a loss of appetite may make it difficult to stick to a healthy diet and eat regularly.

Precautions and measures to prevent the flu or a cold

Preventing a cold or the flu is the first step in protecting your health while managing diabetes. Practice the following tips to prevent contracting these illnesses:

  • Get a flu shot
  • Eat a healthy diet
  • Exercise regularly
  • Wash your hands frequently.

If you are vomiting or have diarrhea, seek medical help. Dehydration can occur rapidly if you have either of these symptoms and can result in serious health complications.

Talk to your healthcare provider and your diabetes management team if you are sick and need help managing your blood glucose levels.