Blood glucose (or blood sugar) is your body’s main energy source. When you have an abnormally low level of blood sugar, your body’s ability to properly function may be impaired as a result. This condition is called hypoglycemia, and it’s officially defined as a blood glucose level of below 70 milligrams per deciliter (mg/dL).

Hypoglycemia is most common in people with diabetes. However, a few other conditions — most of them rare — can also cause low blood sugar.

Your brain needs a constant, steady supply of glucose. It can’t store or manufacture its own energy supply, so in the event your glucose level drops, your brain may be affected by the hypoglycemia. You may experience some of these symptoms:

  • unusual behavior, confusion, or both (this may manifest as an inability to complete routine tasks or remember information you would otherwise have no trouble recalling)
  • loss of consciousness (uncommon)
  • seizures (uncommon)
  • visual disturbances, such as double or blurred vision

Hypoglycemia may also cause other physical symptoms:

  • anxiety
  • heart palpitations
  • hunger
  • sweating
  • tremors

Because these signs aren’t specific to hypoglycemia, it’s important that you measure your blood sugar level when these symptoms occur if you’re diabetic. It’s the only way to know if they are caused by a blood glucose problem or another condition.

If you have diabetes, your body’s ability to use insulin is impaired. Glucose can build up in your bloodstream and may reach dangerously high levels (hyperglycemia). To correct this, you may take insulin injections or a series of other drugs that will help your body lower your blood sugar level. In the event you take too much insulin relative to the amount of glucose in your bloodstream, you may experience a blood sugar level drop, which can result in hypoglycemia.

Another possible cause: If you take your diabetes medication or give yourself an insulin injection, but you don’t eat as much as you should (taking in less glucose) or exercise too much (using up glucose), you may also experience a drop in blood glucose.

The approach to treating hypoglycemia is twofold: what needs to be done immediately to bring your blood sugar level back to normal, and what needs to be done in the long term to identify and treat the cause of hypoglycemia.

Immediate treatment

The initial treatment for hypoglycemia depends on what symptoms you’re experiencing. Typically, consuming sugar, such as candy or fruit juice, or taking glucose tablets can treat early symptoms and raise your blood sugar back to a healthy level. However, if your symptoms are more severe, and you’re unable to take sugar by mouth, you may need an injection of glucagon or an IV with glucose given either at the hospital or by emergency medical service.

Long-term treatment

Your doctor will want to work with you to identify what has caused your hypoglycemia. If they believe it’s related to your diabetes, they may suggest you begin using medication, adjust your dosages if you’re already on medicine, or find a new approach to lifestyle management. If your doctor determines your hypoglycemia is the result of another issue unrelated to your diabetes, such as a tumor or illness, they may recommend you to a specialist to treat that problem.

Ignoring the symptoms of hypoglycemia can be costly. A lack of glucose may shut your brain down, and you may lose consciousness.

Untreated hypoglycemia can lead to:

  • loss of consciousness
  • seizure
  • death

If you’re a caretaker for someone with diabetes who begins experiencing one of these symptoms, seek emergency help immediately.

If you have diabetes, take care to not over-treat low blood sugar. You may end up causing your blood sugar level to rise too high. This fluctuation between low and high blood sugar may cause damage to your nerves, blood vessels, and organs.

If you have previously experienced hypoglycemia, the key to preventing a future problem is understanding what caused the issue in the first place and then carefully following your diabetes management plan.