Managing High and Low Blood Sugar With Diabetes

Here’s how to prevent hypoglycemia and hyperglycemia.

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If you have diabetes, you know that keeping your blood sugar within a healthy range is important. You may also know that your blood sugar levels may rise (hyperglycemia) or fall (hypoglycemia), depending on what you eat, your physical activity levels, your medication doses, and other factors, such as whether you’re sick with a cold or other infection. The key to keeping blood sugar under control is to be able to identify symptoms of low and high blood sugar, and have a plan of action to get your levels stable again.

What Is Low Blood Sugar and What Are the Symptoms?

Low blood sugar, or hypoglycemia, is when your blood glucose measures less than 70 mg/dL. This can happen if you don’t eat enough or wait too long between meals, exercise without eating, take too much medicine (insulin or certain diabetes pills), or drink too much alcohol.

Symptoms of low blood sugar can vary from person to person, but some early signs may be:

  • feeling excessively hungry
  • sweating a lot
  • feeling anxious or worried
  • heart palpitations
  • tremors

How Should You Treat Low Blood Sugar?

If you have low blood sugar, the first thing you should do is look for something sweet to drink, like orange juice. “It’s the fastest way to get sugar into your system,” says Sandra Arévalo, RDN, CDE.

Fast-acting carbohydrate sources (15 g):

  • 3 to 4 glucose tablets
  • milk (8 oz) or juice (4 oz)
  • a spoonful of sugar or honey (1 Tbsp)
  • a couple spoonfuls of raisins (2 Tbsp)
  • 6 to 8 hard candies

Follow the 15/15 Rule for Low Blood Sugar

A good way to make sure you blood sugar has returned to a healthy level without going too high is to apply the 15/15 rule, or eating 15 grams of carbs and checking your blood sugar after 15 minutes. If your blood glucose is 51 to 70 mg/dL, eat 10 to 15 grams of a fast-acting carbohydrate. If it’s less than 50 mg/dL, eat 20 to 30 grams.

What Is High Blood Sugar and What Are the Symptoms?

High blood sugar (hyperglycemia) is when your blood sugar exceeds 160 to 250 mg/dL, or your individual blood glucose target. This can happen if you didn’t give yourself enough insulin (type 1) or your body isn’t using it properly (type 2). Hyperglycemia can also occur if you ate too much, are stressed or sick, or if you experienced the dawn phenomenon (a surge of hormones that the body produces daily around 4:00 a.m.).

Symptoms of high blood sugar also vary, and some people may actually not feel any symptoms of hyperglycemia. Common signs may include:

  • increased thirst
  • frequent urination
  • dry, itchy skin
  • weight loss
  • fatigue
  • blurry vision
  • headache
  • feeling nauseous or faint

How Is High Blood Sugar Treated?

A great way to remedy high blood sugar is to exercise. However, if your blood glucose exceeds 240 mg/dL, you should check your urine first for ketones. If ketones are present, don’t exercise—doing so may actually cause your blood sugar go higher.

You can also treat your high blood sugar with insulin, if you take it. It’s also important to stay hydrated and watch your diet to make sure you’re not eating too many carbohydrates.

How Should You Prevent High and Low Blood Sugar?

The best way to keep your levels under control is to practice good diabetes management and check your blood sugar regularly. It’s also important to know the early symptoms so you can stop hyperglycemia or hypoglycemia in its tracks and, importantly, prevent it from getting worse.