What Is Low Blood Sugar (Hypoglycemia)?
Low blood sugar (hypoglycemia) occurs when the level of sugar (glucose) in a person's blood gets too low, usually below 70 mg/dL.
Most cases of low blood sugar occur in people who have diabetes. It is not common in people who are not diabetic. People who don’t have diabetes may feel as if they have low blood sugar, but they likely do not.
What Are Symptoms of Low Blood Sugar (Hypoglycemia)?
Early symptoms of low blood sugar can include:
If low blood sugar levels are not treated, severe symptoms may occur which can include:
- Headache
- Blurred vision/other vision problems
- Dizziness
- Weakness
- Trouble walking
- Fast heartbeat
- Tingling or numbness in the lips, tongue or cheeks
- Confusion
- Not thinking clearly
- Acting strangely
- Lightheadedness
- Fainting
- Seizure
Some people with diabetes do not have symptoms during the early stages of low blood sugar in what is called “hypoglycemia unawareness.” Because people with hypoglycemia unawareness do not have symptoms, they do not treat their low blood sugar early on, and they are more likely to have severe symptoms. Hypoglycemia unawareness often occurs in people who:
- Have had type 1 diabetes for more than 5 to 10 years
- Use insulin to control blood sugar levels
- Are tired
- Drink a lot of alcohol
- Take medicines for high blood pressure or diabetes
What Causes Low Blood Sugar (Hypoglycemia)?
Causes of low blood sugar (hypoglycemia) in people with diabetes include:
- Taking too much medicine, including insulin or certain oral diabetes drugs
- Not eating enough food
- Exercising too much without eating a snack or reducing the insulin dose
- Waiting too long between meals
- Drinking too much alcohol
Causes of low blood sugar in people without diabetes include:
- Certain medicines
- Medicines to treat diabetes, including insulin
- Sulfamethoxazole and trimethoprim (Bactrim)
- Beta-blockers
- Haloperidol
- Monoamine oxidase inhibitors (MAOIs)
- Pentamidine
- Quinidine
- Sulfonylureas
- Drinking too much alcohol
- Liver or kidney problems
- Hypothyroidism
- Anorexia nervosa
- Problems in the pancreas
- Side effects of weight loss surgery
- Genetic disorder
How Is Low Blood Sugar (Hypoglycemia) Diagnosed?
Low blood sugar (hypoglycemia) is diagnosed when a person has symptoms of low blood sugar and:
- Has low blood sugar levels when symptoms occur
- This may be measured with a blood test from a blood glucose meter
- Feels better after eating something that raises blood sugar levels to normal
To determine the cause of low blood sugar, tests that may be indicated include:
- Blood tests
- Computerized tomography (CT) scan
- Magnetic resonance imaging (MRI) scan
- Ultrasound
What Is the Treatment for Low Blood Sugar (Hypoglycemia)?
Treatment for low blood sugar (hypoglycemia) includes:
- Consuming quick sources of sugar
- Glucagon, a hormone
- Quickly raises blood sugar levels and stops severe symptoms
- Comes as a shot or a nose spray