What is a Sick Day?

A sick day is when you have a sickness like the flu, an infection, nausea, vomiting, diarrhea, surgery, injury, or even a minor illness like a cold.  Knowing what to do when you are sick is important when you have diabetes because your insulin or medication needs may change.

What causes your blood sugar to rise when you are sick?

  • Your body reacts to sickness by releasing hormones that help you fight illness. These hormones may cause the blood sugar levels to rise and keep your diabetes medications from working well.
  • You may be drinking or eating less than usual or you may be vomiting.  If you become dehydrated, it can change how your medications work.


Foods and fluids to have when you are sick

If able to eat:

  • Drink 4 oz. – 8 oz. of fluid every 1- 2 hours, extra fluid is needed to prevent dehydration
  • Calorie-free, caffeine-free liquids are best (water, diet soda, broth)

If unable to eat:

  • Drink 4 oz. – 8 oz. of fruit juice or 6 oz. regular soda every hour
  • Drink liquids that contain salt and electrolytes (sports drinks) every

      3 hours

If having difficulty eating:

  • Eat or drink 15 grams of carbohydrate every hour

Foods with 15g Carbohydrate:

½ cup pudding                      1 regular popsicle                ½ cup regular Jello

8 oz Gatorade                       ½ cup applesauce               ½ cup yogurt

1 slice of toast                       1 cup soup                            6 saltines

1 cup milk                              3 sq. graham crackers        ½ cup ice cream

Sick Day Guidelines

You may need to stop some oral medications if you are sick - Do not take metformin (Glucophage) or SGLT2 inhibitors (Empagliflozin (Jardiance), Canagliflozin (Invokana), Dapagliflozin (Farxiga) or sulfonylureas (Glipizide, Glimepiride) if vomiting or not eating and drinking well.

Call your doctor if you are not sure which medications to take

  • Check blood sugar often (every 2- 4hours) day and night
  • If you take insulin, extra insulin may be needed when sick  check for urine ketones if your blood sugar is over 250 mg/dL and you have type 1 diabetes or ketosis prone diabetes (see below)

When you should call your provider

  • If you have a fever > 100° for more than 24 hours that does not improve with acetaminophen (Tylenol).
  • If you have been vomiting or having diarrhea for >6 hours.
  • If you have a blood sugar over 250 mg/dl or higher that does not get better with extra insulin and fluids for > 24 hours.
  • If you have moderate to large ketones in your urine (type 1). 
  • If you have stomach pain or difficulty breathing. 
  • If you are unsure of what to do.
  • Get emergency care if you cannot reach your provider.


Insulin helps turn sugar into energy in the body. If your body has too little insulin available it looks for other kinds of energy, such as fat. When fat is used as energy, this can cause ketones to be produced in the body. These go into your bloodstream and get removed by your kidneys when you urinate. If the level of KETONES become too high a serious problem called diabetes ketoacidosis can develop.  

When should you test for ketones?

  • If your blood sugar is > 250 mg/dl or higher for two tests in a row
  • If you are sick
  • If you develop vomiting or diarrhea
  • If you are stressed
  • If you are pregnant and blood sugar is high

How to test?

A special test strip for urine ketones can be dipped in a sample of your urine.  If there is a color change on the strip, there are ketones. (There are also meters which can be used to test your blood for ketones).  The color result indicates a small, medium or large amount of ketones

Remember, if your blood sugar is high, you may need extra insulin even if you are not eating or drinking well:

If results are trace or small ketones

  • Calculate your correction dose and inject short acting insulin with your insulin pen or vial and syringe










Your BG


Target BG


How much higher is your BG


Correction Factor


Amount of short acting insulin needed



  • Take 10% of your total daily dose with short acting insulin (TDD = long acting insulin dose plus total short acting insulin you take per day)

Your TDD x 0.1 (10%) = Your correction dose

  • Continue your insulin doses and activities as usual 

Moderate to large ketones:  

  • Calculate a correction dose by taking 20% of your total daily dose via short acting insulin which you can calculate from your total basal insulin dose plus the total amount of short acting insulin you take per day:






Your TDD




Your correction dose


  • Re-check your glucose in 2-3 hrs. If your glucose decreases, continue your insulin doses as usual.
  • If you are using a continuous glucose monitor (CGM) watch for a downward arrow on your monitor, confirm your blood sugar with a fingerstick if you have not seen a change on your CGM
  • Drink plenty of water – at least 8 ounces every hour
  • If your blood glucose does not decrease or is higher:
    • Re-check for urine ketones
    • Take an additional correction dose based on ketone level as above
  • If your blood glucose doesn’t decrease or if you are feeling worse, call your doctor or seek emergency care