A person with type 1 diabetes (T1D) may be more at risk of developing complications of flu. This may be due to the flu raising blood sugar levels or the immune system not functioning effectively.

Type 1 diabetes (T1D) is a chronic autoimmune condition that occurs when the immune system mistakenly attacks the beta cells of the pancreas. Damage to these cells means the body can no longer produce insulin, a hormone responsible for regulating blood sugar levels.

As such, people with T1D must manually manage their blood sugar levels to avoid them becoming too high or too low.

As T1D is an autoimmune condition, those with it may have immune system issues. This may mean they are more prone to infections, such as the flu. Additionally, when the body is ill, it often produces and releases stress hormones. These hormones can cause blood sugar levels to rise, meaning those with T1D will need to take extra care to manage their blood sugar, which is also known as blood glucose.

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T1D is an autoimmune condition where the body mistakenly attacks healthy cells. When a person has T1D, the immune system mistakenly attacks the pancreas. As such, people living with autoimmune conditions may find it harder to fight off infections, such as the flu.

According to the Centers for Disease Control and Prevention (CDC)Trusted Source, people with T1D may have a weaker immune system. However, there is currently no evidence to support that a person with T1D will be more likely to contract the flu. However, the CDC suggests that a person with T1D is more likely to experience severe side effects of the flu.

The National Foundation for Infectious Diseases (NFID) notes that individuals with diabetes are at a higher risk of complications from the flu. For example, evidence suggests that those with T1D and flu are more likely to experience complications such as stroke or heart attack.

According to the American Diabetes Association (ADA), the flu causes the body to release stress hormones such as adrenaline or cortisol. These hormones trigger the liver to produce more glucose and make cells more resistant to insulin, leading to increased blood sugar levels.

When someone with T1D does not have enough effective insulin, their body starts to burn fat quickly for fuel. This can lead to a rise in levels of a chemical known as ketones. When ketone levels are too high, a person can develop a serious and potentially life threatening complication of diabetes known as diabetic ketoacidosis (DKA).

There are several ways someone with T1D can manage the flu. It can be helpful to have a plan in place in case they get sick with the flu, such as:Trusted Source

  • checking blood glucose levels every 4 hours
  • continuing to take diabetes medications as usual
  • avoiding taking any over-the-counter flu medications without advice from a healthcare professional as some can raise blood sugar levels
  • drinking plenty of water
  • eating small amounts regularly
  • monitoring ketone levels
  • regularly checking their temperature

A person with T1D may want to have some supplies at home that can help if they do get sick with the flu, including:

  • ketone tests
  • glucose tabs, gels, sports drinks, fruit juices, or sodas
  • at least 1 week’s supply of diabetes medication
  • a glucose meter with extra batteries
  • easy to prepare foods such as canned soups, instant cereal, crackers, instant pudding, and unsweetened applesauce

Symptoms of the flu typically come on suddenly and can be mild to severe. A person with T1D may experience more severe symptoms as the immune system may not be workingTrusted Source as effectively.

According to the CDCTrusted Source, symptoms of the flu typically include:

  • sore throat
  • aching and tender muscles and body
  • runny or blocked nose
  • cough
  • fever
  • fatigue
  • headaches
  • vomiting
  • diarrhea

There are several ways individuals with T1D can protect themselves from the flu. According to the National Institutes of Health (NIH)Trusted Source, the most effective way of preventing the flu is to have the flu vaccine annually if a person is over the age of 6 months.

A 2023 studyTrusted Source suggests that the flu vaccine can reduce the risk of serious complications in those with diabetes. Similarly, a 2023 systematic review concludes that vaccination is an effective option for preventing such complications in people living with diabetes.

Other ways a person with diabetes can help prevent the flu include:

  • avoiding close contact with anyone who has the flu
  • frequently cleaning surfaces at home or at work
  • washing hands regularly
  • avoiding touching the mouth, nose, and eyes

A person with T1D may be at higher riskTrusted Source of developing complications of the flu, including pneumonia. Individuals need to contact a healthcare professional if they experience any of the following symptoms of flu complications:

  • severe muscle aches or weakness
  • breathlessness
  • dizziness, confusion, unsteadiness, weakness, confusion, or difficulty rousing
  • persistent chest pain
  • persistent abdominal pain
  • not passing any urine
  • a cough or fever that seems to improve then worsens

A person with T1D and the flu may be more at risk of developing DKA if ketone levels get too high. DKA can be life threatening, so it is important that those with diabetes and the flu seek urgent medical attention if they experience any of the following:

  • urinating frequently
  • excessive thirst or dry mouth
  • feeling drowsy
  • dry skin
  • flushed skin
  • nausea
  • vomiting
  • pain in the abdomen
  • having a fruity odor on the breath
  • confusion
  • breathlessness or difficulty breathing

A person with type 1 diabetes (T1D) may have a higher risk of developing serious complications of the flu, such as pneumonia. This may be due to the immune system not working as effectively and the flu causing blood sugar levels to rise.

If someone with T1D develops the flu, they need to regularly test their blood sugar levels, drink plenty of water, avoid certain over-the-counter flu medications, and eat small amounts of food regularly.

A person with diabetes may be able to help prevent the flu by having the flu vaccination, regularly washing hands, cleaning surfaces, and avoiding close contact with individuals with the flu.