What does it mean when your glucose level is low

summary

Hypoglycemia is a condition in which the level of sugar (glucose) in the blood is lower than the standard range. Glucose is your body’s main source of energy.

Hypoglycemia is often related to the treatment of diabetes. But other medications and a variety of conditions (many rare) can cause low blood sugar in people who don’t have diabetes.

Hypoglycemia needs immediate treatment. for many people, a fasting blood sugar level of 70 milligrams per deciliter (mg/dl), or 3.9 millimoles per liter (mmol/l), or less, should serve as a hypoglycemic alert. but their numbers may be different. ask your health care provider.

Treatment involves bringing your blood sugar back into the standard range quickly, either with a high-sugar food or drink, or with medication. long-term treatment requires identifying and treating the cause of the hypoglycemia.

symptoms

If blood sugar levels drop too low, signs and symptoms of hypoglycemia may include:

• look pale
• tremors
• sweating
• headache
• hunger or nausea
• irregular or fast heartbeat
• fatigue
• irritability or anxiety
• difficulty concentrating
• dizziness or lightheadedness
• tingling or numbness of the lips, tongue, or cheeks

As hypoglycemia worsens, signs and symptoms may include:

• confusion, unusual behavior, or both, such as an inability to complete routine tasks
• loss of coordination
• difficulty speaking
• blurred vision or tunnel vision
• nightmares, if asleep

severe hypoglycemia can cause:

• non-response (loss of consciousness)
• seizures

when to see a doctor

Seek medical help immediately if:

• has what could be symptoms of hypoglycemia and does not have diabetes
• has diabetes and hypoglycemia does not respond to treatment, such as drinking juice or regular (non-diet) soda, eating sweets, or taking glucose tablets

Seek emergency help for someone with diabetes or a history of hypoglycemia who has symptoms of severe hypoglycemia or loses consciousness.

causes

Hypoglycemia occurs when the level of sugar (glucose) in the blood is too low for bodily functions to continue. there are several reasons why this can happen. The most common reason for low blood sugar is a side effect of medications used to treat diabetes.

blood sugar regulation

When you eat, your body breaks down food into glucose. Glucose, your body’s main source of energy, enters cells with the help of insulin, a hormone produced by the pancreas. insulin allows glucose to enter cells and provide the fuel they need. the extra glucose is stored in the liver and muscles as glycogen.

When you haven’t eaten for several hours and your blood sugar drops, you’ll stop making insulin. Another hormone from your pancreas called glucagon signals your liver to break down stored glycogen and release glucose into your bloodstream. this keeps your blood sugar level within a standard range until you eat again.

Your body also has the ability to produce glucose. this process occurs mainly in the liver, but also in the kidneys. With prolonged fasting, the body is able to break down fat stores and use the breakdown products of fat as an alternative fuel.

possible causes, with diabetes

If you have diabetes, you may not make insulin (type 1 diabetes) or may be less responsive to it (type 2 diabetes). As a result, glucose builds up in the bloodstream and can reach dangerously high levels. To correct this problem, you may take insulin or other medications to lower blood sugar levels.

But too much insulin or other diabetes medications can cause your blood sugar to drop too low and cause hypoglycemia. Hypoglycemia can also occur if you eat less than usual after taking your regular dose of diabetes medicine or if you exercise more than usual.

possible causes, without diabetes

Hypoglycemia in people without diabetes is much less common. causes may include:

• Medications. Accidentally taking someone else’s oral diabetes medication is a possible cause of hypoglycemia. Other medications can cause hypoglycemia, especially in children or people with kidney failure. one example is quinine (qualaquin), used to treat malaria.
• excessive alcohol consumption. Drinking heavily without eating can prevent the liver from releasing glucose from its glycogen stores into the bloodstream. this can cause hypoglycemia.
• some serious diseases. Serious liver diseases, such as severe hepatitis or cirrhosis, severe infection, kidney disease, and advanced heart disease can cause hypoglycemia. Kidney disorders can also prevent your body from excreting medications properly. this can affect glucose levels due to the buildup of medications that lower blood sugar levels.
• Long-term starvation. Hypoglycemia can occur with malnutrition and starvation when you don’t get enough food, and the glycogen stores your body needs to create glucose are depleted. an eating disorder called anorexia nervosa is an example of a condition that can cause hypoglycemia and lead to long-term starvation.
• Overproduction of insulin. A rare tumor of the pancreas (insulinoma) can cause you to produce too much insulin, resulting in hypoglycemia. other tumors can also cause excessive production of insulin-like substances. unusual cells in the pancreas that produce insulin can cause too much insulin to be released and cause hypoglycemia.
• hormone deficiencies. Certain tumor disorders of the adrenal gland and pituitary gland can cause an inadequate amount of certain hormones that regulate glucose production or metabolism. children can get hypoglycemia if they have too little growth hormone.

hypoglycemia after meals

Hypoglycemia usually occurs when you haven’t eaten, but not always. Sometimes symptoms of hypoglycemia occur after certain meals, but exactly why this happens is not known.

This type of hypoglycemia, called reactive hypoglycemia or postprandial hypoglycemia, can occur in people who have had surgery that interferes with normal stomach function. the surgery most commonly associated with this is stomach bypass surgery, but it can also occur in people who have had other surgeries.

complications

Untreated hypoglycemia can cause:

• seizure
• comma
• death

Hypoglycemia can also cause:

• dizziness and weakness
• falls
• injuries
• motor vehicle accidents
• increased risk of dementia in older adults

hypoglycemia unawareness

Over time, repeated episodes of hypoglycemia can make you unaware of hypoglycemia. the body and brain no longer produce warning signs and symptoms of low blood sugar, such as tremors or irregular heartbeats (palpitations). when this happens, it increases the risk of severe and life-threatening hypoglycemia.

If you have diabetes, recurrent episodes of hypoglycemia, and hypoglycemia unawareness, your healthcare provider may modify your treatment, increase your blood sugar goals, and recommend blood glucose awareness training.

A continuous glucose monitor (cgm) is an option for some people who are unaware of hypoglycemia. the device can alert you when your blood sugar level is too low.

undertreated diabetes

If you have diabetes, episodes of low blood sugar are uncomfortable and can be scary. Fear of hypoglycemia may cause you to take less insulin to make sure your blood sugar doesn’t drop too low. this can lead to uncontrolled diabetes. talk to your health care provider about your fear, and don’t change the dose of your diabetes medication without discussing the changes with your health care provider.

prevention

if you have diabetes

Follow the diabetes management plan that you and your health care provider have developed. If you are taking new medications, changing your meal or medication schedules, or adding new exercises, talk with your health care provider about how these changes might affect your diabetes control and your risk of low blood sugar.

Learn the signs and symptoms you experience with low blood sugar. this can help you identify and treat hypoglycemia before it gets too low. Checking your blood sugar often lets you know when your blood sugar is getting low.

A continuous glucose monitor (cgm) is a good option for some people. An cgm has a small wire that is inserted under the skin that can send blood glucose readings to a receiver. If blood sugar levels are getting too low, some cgm models will alert you with an alarm.

Some insulin pumps are now integrated with cgms and can stop insulin delivery when blood sugar levels are falling too quickly to help prevent hypoglycemia.

Be sure to always have a fast-acting carbohydrate on hand, such as juice, hard candy, or glucose tablets so you can treat a low blood sugar before it becomes dangerously low.

if you don’t have diabetes

For recurrent episodes of hypoglycemia, eating small, frequent meals throughout the day is a stopgap measure to help prevent blood sugar levels from falling too low. however, this approach is not recommended as a long-term strategy. work with your health care provider to identify and treat the cause of hypoglycemia.