Checking Blood Sugar When Ill

When you are sick, blood sugar can change quickly, even when you eat less. Checking on a schedule helps you spot changes early. The American Diabetes Association suggests checking every 2 to 4 hours. Your plan sets the exact times.

Call your care team if a reading stays above 300 mg/dL (16.7 mmol/L). Do this if it lasts more than a few hours, even after treatment.

Wash and dry your hands first. Sugar on wet or dirty hands can make a reading falsely high. Then test, and write down the time and reading.

Also note your symptoms and whether fluids stayed down. Call your care team if you cannot keep fluids down for 4 hours.

A bedside table under a wall clock. Fluids shows a glass and a bottle of water. Check more shows a meter and a notepad, with ticks every few hours on the clock. Eat small shows crackers and soup. Call shows a phone, with four hours shaded on the clock.

Ketones are acids your body makes when it cannot use sugar well for energy.

Check for ketones when your blood sugar runs high or you feel worse. Many adults on insulin check at about 240 mg/dL (13.3 mmol/L) or higher. Follow what your plan directs (sources differ).

Write each ketone result next to its blood sugar reading.

Key takeaways

• Space checks about 2 to 4 hours apart while you are sick.
• Wash and dry your hands, then log the time, reading, symptoms and fluids.
• Check ketones when readings run high or you feel worse, as your plan directs.

Try it

Before you need it, make a log page with columns for time, reading, symptoms and fluids kept down.