What Is Low Blood Sugar?

Low blood sugar, also called hypoglycemia, happens when the amount of glucose in your blood drops too low. Glucose gives your body energy, especially for your brain and muscles. When levels fall, your body may not function normally.

Hypoglycemia is often caused by:

• Taking too much insulin or diabetes medication
• Skipping meals or eating later than usual
• Exercising harder or longer than expected
• Drinking alcohol without eating
• Fasting for long periods

Hypoglycemia is most common in people with diabetes, especially those who use insulin or certain diabetes medicines. It can also happen for other reasons, including long periods without food, intense exercise, or certain medical conditions.

Symptoms

Low blood sugar can come on suddenly. Symptoms may range from mild to severe depending on how low your blood sugar becomes.

Common symptoms include:

• Shaking or trembling
• Sweating
• Hunger
• Dizziness
• Headache
• Fast heartbeat
• Blurred vision
• Irritability or mood changes
• Trouble concentrating
• Confusion
• Weakness or fatigue

Some people experience symptoms while sleeping, such as nightmares, restless sleep, or waking up sweaty and tired.

How Is It Diagnosed?

Your healthcare provider will ask about your symptoms, medical history, medications, and eating habits. Blood tests are used to measure glucose levels and confirm whether your symptoms are caused by hypoglycemia.

If episodes happen often or occur in someone without diabetes, additional testing may help identify an underlying cause.

How Is It Treated?

Treatment depends on how severe the episode is and what caused it.

For mild symptoms, blood sugar can usually be raised quickly by eating or drinking fast-acting carbohydrates, such as:

• Fruit juice
• Glucose tablets
• Regular soda
• Hard candy

After treatment, blood sugar should be checked again to make sure it returns to a healthy range. A meal or snack may help keep levels stable afterward.

People with severe hypoglycemia may need emergency treatment, including glucagon medication or medical care.

Long-term treatment focuses on preventing future episodes. Your provider may recommend:

• Adjusting diabetes medications
• Eating meals and snacks on a regular schedule
• Monitoring blood sugar more often
• Planning ahead for exercise
• Limiting alcohol use

Most people recover quickly once blood sugar levels improve, but severe untreated hypoglycemia can become dangerous if not treated promptly.