If Your Blood Glucose is Too High or Too Low

Hyperglycemia & Hypoglycemia

Blood glucose that gets too high or too low can be dangerous. To stay safe and healthy, check your blood glucose regularly and watch for certain symptoms, like being very hungry, tired or sleepy. If your blood glucose is outside the normal range, take the steps described below to start feeling better.

High Blood Glucose: Hyperglycemia

Hyperglycemia means that you have too much blood glucose. It happens when your blood glucose level is around 200 mg/dL or higher. Hyperglycemia can happen if you miss taking your diabetes medications, eat too much or do not get enough exercise. Sometimes, the medications you take for other problems cause high blood glucose.

Symptoms of hyperglycemia include:

  • Being very thirsty
  • Being very tired
  • Having blurry vision
  • Having to urinate often

If you have these symptoms, check your blood glucose right away. If it’s too high, follow these steps:

  • Check your blood glucose every four hours. If your level does not go down after two checks or your symptoms get worse, call a member of your diabetes team.
  • Drink water or other sugar-free liquids, such as diet soda or Crystal Light.
  • You may need to take an extra dose of insulin. Your diabetes educator talks with you more about this.

High Blood Glucose: Diabetic Ketoacidosis (DKA)

If your insulin level is too low, your blood glucose could become so high that it is unsafe. You might develop a serious problem called diabetic ketoacidosis (or DKA). This usually happens in people with Type 1 diabetes and those with glucose levels over 500.

If you have DKA, chemicals called ketones start to make a lot of acid in your body. The acid and high blood glucose can make you very sick. You might also become dehydrated (lose body fluid). You can prevent DKA by carefully giving yourself the correct insulin dose every day.

If you have any of the following symptoms of DKA, get to your local emergency department right away. You need to be treated with insulin and fluids that are given to you through an IV (a thin tube placed in your arm):

  • Blurry vision
  • Decreased appetite
  • Dry mouth, eyes or skin
  • Fast breathing
  • Feeling confused or irritable
  • Feeling very weak or tired
  • Fruity-smelling breath
  • Stomach pain, nausea or vomiting

Low Blood Glucose: Hypoglycemia

Hypoglycemia can occur when blood glucose drops below normal levels or drops too quickly. Your blood glucose level is too low if it is under 70 mg/dL.

Hypoglycemia can be caused by:

  • A combination of these factors
  • Being more active than usual
  • Drinking alcohol
  • Eating at the wrong time for the medications you take
  • Skipping or not finishing meals or snacks
  • Taking too much diabetes medication

You can have hypoglycemia without any symptoms. That makes it important to check your blood glucose levels regularly. When hypoglycemia does cause symptoms, they can include:

  • Being sweaty
  • Fast heartbeat
  • Feeling irritable
  • Feeling shaky
  • Feeling tired
  • Headache
  • Hunger

If you have these symptoms, check your blood glucose right away. If it is too low (under 70 mg/dL), take something with sugar right away. This quickly raises your blood glucose level. Some good options include:

  • Five to six hard candies
  • One-half cup (4 oz) of fruit juice or regular soda
  • Three glucose tablets

You should also check your blood glucose again after 15 minutes. If it’s still low, again take something with sugar. Check your blood glucose level again after another 15 minutes. If it is still low, call a member of your diabetes team. If your next meal is more than an hour away, eat a small snack.

*The content on this website is for informational purposes only and is not medical advice. Please consult a physician regarding your specific medical condition, diagnosis and/or treatment.