diabetes with fever

Overview

When you have diabetes, a fever is more than just a nuisance. It can affect your blood sugar levels and may be a sign of an infection that needs treatment. Learning how to manage a fever with diabetes can help you stay safe and recover more quickly.

Yes. People with diabetes get fevers just like anyone else, but the combination needs extra care.

Anyone with diabetes, but especially people who use insulin, older adults, and those with other diabetes-related health conditions.

Symptoms

Common symptoms

• Fever (temperature at or above 100.4°F / 38°C)
• Chills and sweating
• Feeling weak or tired
• Increased thirst and frequent urination
• Dry mouth
• Flushed skin

Causes

Main causes

• Viral infections (such as colds, flu, or COVID-19)
• Bacterial infections (such as urinary tract infections, pneumonia, or skin infections)
• Sometimes heat exhaustion or dehydration can cause a low-grade fever

Risk factors

• High blood sugar over a long period
• Diabetes complications, such as kidney or nerve problems
• Use of injected insulin
• Being over 65 years old
• Having a weakened immune system

When to see a doctor

See a doctor urgently if:

• If your temperature reaches 100.4°F (38°C) or higher, contact your diabetes care team the same day.
• If you are vomiting and cannot keep fluids down.
• If your blood sugar is persistently above 250 mg/dL (13.9 mmol/L) despite taking your medicines.
• If you have ketones in your urine (if you check them) and feel sick.

Book a routine appointment if:

• If you have a routine diabetes check-up coming up, keep it even if you feel fine.
• If you are not sure how to adjust your diabetes medicine when you are ill, ask your doctor or diabetes nurse in advance.

Diagnosis

Your care team will ask about your symptoms, check your temperature, and likely test your blood sugar. They may also check your urine for ketones or take blood samples to find the cause of the fever.

Tests that may be done

• Blood glucose (sugar) test
• Urine test for ketones and signs of a urinary tract infection
• Blood tests to check for infection and blood sugar control
• Possibly a chest X-ray or throat swab, depending on your symptoms

What to expect at your appointment

The appointment may be by phone or in person. The provider will review your diabetes management, ask about your medicines, and help you make a sick-day plan. They will tell you how often to check your blood sugar and when to call again.

Treatment

The goal is to control your fever, keep your blood sugar in a safe range, and treat the underlying cause, such as an infection. Your diabetes medicines may need to be adjusted temporarily, so always follow your care team’s advice.

Self-care at home

• Drink plenty of water or sugar-free fluids to stay hydrated.
• Check your blood sugar more often than usual — at least every 4 to 6 hours.
• Get plenty of rest and avoid physical exertion.
• Follow your 'sick-day rules' if your diabetes team gave them to you.
• If you use insulin, never stop taking it unless your healthcare provider tells you to.

Medical treatments

Depending on the cause, your doctor may recommend fever-reducing medicines, antibiotics for bacterial infections, or extra fluids. They may also adjust your diabetes medication to match your changing needs. Any medicine should be taken exactly as prescribed — never change your diabetes medicine on your own without medical advice.

When is surgery considered?

Surgery is not usually needed for diabetes with fever. It may be necessary if there is an infection that requires drainage, but this is uncommon.

Living with this condition

Having diabetes with a fever is stressful, but most people recover at home. Check your blood sugar regularly, stay in touch with your care team, and tell someone how you are feeling. Keep simple supplies like a thermometer, plenty of fluids, and your diabetes medicines within reach.

Lifestyle tips

• Keep up to date with routine diabetes check-ups.
• Get enough sleep and reduce stress during illness.
• Wash your hands often to avoid spreading infections.

Diet and exercise

If you have a fever, try to eat small snacks or meals that match your usual diabetes meal plan. If you cannot eat solid food, choose clear soups or sugar-free jelly. But do not skip carbohydrates completely — check with your doctor if you are unsure. Avoid strenuous exercise while ill, but gentle movement may help once you recover.

Mental health and emotional wellbeing

Dealing with a fever on top of diabetes can feel worrying and exhausting. It is normal to feel anxious or frustrated. Talk to your healthcare team or a trusted friend. Remember that you are doing the right thing by seeking care.

Prevention

You cannot prevent every infection or fever, but good diabetes control can make infections milder and help you recover faster. Getting vaccinated is also a key step.

Vaccines

Ask your doctor about recommended vaccines, including influenza (flu), pneumococcal pneumonia, COVID-19, and hepatitis B. People with diabetes may be eligible for these at no charge.

Screening programmes

Regular checks of your blood sugar (HbA1c), kidneys, eyes, and feet help keep your body resilient. Annual flu shots and timely boosters are part of good diabetes care.

Complications

If left untreated

• Very high blood sugar leading to diabetic ketoacidosis (DKA), more common in type 1 diabetes
• Hyperosmolar hyperglycemic state (HHS), more common in type 2 diabetes
• Severe dehydration and electrolyte imbalances
• Worsening of the infection, such as pneumonia or a bloodstream infection (sepsis)

Long-term outlook

With early attention, most people with diabetes and a fever recover fully. Monitoring your blood sugar, staying hydrated, and following medical advice can make a big difference. Your care team will help you through it — you are not alone.

Find support

International organisations

• International Diabetes Federation ↗

Local organisations

• Diabetes UK ↗ · United Kingdom

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