What are ketones? Diabetes Home Sick days When to follow your sick day plan Go to hospital when What are ketones? How do ketones happen? What to do when you have ketones You have ketones. How do you feel? You have ketones. What do you do? Ketones are in your blood. They can make you very sick. Ketones happen over the day. You may get them when you are sick or your do not take the insulin you need. You can check your ketones. Use your blood sugar meter. or You can use pee strips. The ketone test will tell you a number. Read more about them here. Back Diabetes Home Next This is general information. Talk to your doctor for information made for you.