Diabetes Management: How to Manage Blood Sugar (Blood Glucose) When Sick

You may experience either:

📈 High Blood Glucose Level

• As your body becomes more resistant to the insulin produced or injected.
• When you drink less due to nausea or vomiting.

📉 Low Blood Glucose Level (<4 mmol/L)

• When you eat less due to loss of appetite or nausea.

🩸 Test your Blood Glucose (BG) levels frequently, 4–6 times a day.

In general, aim for Blood Glucose (BG) levels of 4–8 mmol/L before each meal.

Try to maintain a normal meal pattern.

If your BG level is falling but still in range (4–5 mmol/L), and you have little appetite to eat, try to consume some food that contains carbohydrates and is easier to digest.

Examples are :

🍌banana

🥣porridge

🍜noodle soup

If your BG level falls to less than 4 mmol/L, that indicates hypoglycaemia (low blood glucose). Apply the 15/15 Rule and consume 15g of quick-acting carbohydrates:

🧃 ½ glass fruit juice (150ml)

OR 🥤 ½ can soft drink (150ml–200ml)

OR 🍚 3 teaspoons sugar (15g)

Wait 15 minutes and re-test BG level to ensure it is more than 4 mmol/L.

If your BG levels are high (>8 mmol/L), sip sugar-free fluids to ensure you remain well hydrated.

However, if your BG levels are falling but still in range (4-5 mmol/L), and your appetite is poor, consider consuming fluids that contain sugar (e.g. fruit juice).

a) Insulin

In general, DO NOT STOP your insulin injections.

If you have Type 1 diabetes, there are more steps you need to take to keep yourself safe. Please refer to the SgDAFNE Facebook page for more information on course dates.

Sometimes, with the higher BG levels associated with sickness, you may need a higher dose of insulin until you recover from your sickness. In general, if your BG levels are still >10 mmol/L 24 hours after being sick, your background insulin dose may need increasing (e.g. 10% increase).

If you are on more than one insulin injection a day (e.g. twice daily premixed or 4 times daily insulin, consisting of once daily background insulin and 3 quick-acting insulin doses for three meals), the doses of these insulins may need increasing.

☎ Contact your healthcare team if you are uncertain what to do. Remember to decrease the insulin dose back to your usual dose when you recover.

b) Sulphonylurea Tablets

• Gliclazide
• Glipizide
• Glibenclamide
• Tolbutamide
• Glimepiride

These tablets work by increasing the body’s production of insulin regardless of the BG level. If you take this tablet, you MUST NOT skip your meals.

If you take any of these tablets, consider consuming carbohydrates that are easier to eat, such as fruit, rice porridge, or fruit juice. 

If you are unable to eat much carbohydrates, your tablet dose may need to be halved or omitted during this period of time. ☎ If in doubt, seek advice from your healthcare team.

c) SGLT2 Inhibitors

• Empagliflozin
• Dapagliflozin
• Canagliflozin

These tablets work by increasing the amount of glucose passed in the urine. This then results in more water loss through the urine, which can increase the risk of dehydration. In addition, these tablets may also increase the risk of acid (ketones) forming in the blood, particularly on sick days.

Stay well hydrated through this time. If your appetite is reduced, consider replacing meals with carbohydrate snacks or drinks. Your tablet may need to be stopped if you are unable to eat or drink. ☎ Please seek advice from your healthcare team.

Ref: F26