Symptoms of Low Blood Sugar

Topic Overview

Symptoms of mild low blood sugar

You may have these symptoms when your blood sugar has dropped below 70 milligrams per deciliter (mg/dL). When you have had diabetes for many years, you may not always develop symptoms of mild low blood sugar.

Some young children with diabetes cannot recognize symptoms of low blood sugar. Others can, but not every time. To be safe, the parents need to do a home blood sugar test whenever they suspect low blood sugar in a child.

Symptoms may include:

• Sweating (almost always present). Check for sweating on the back of your neck at your hairline.
• Nervousness, shakiness, and weakness.
• Extreme hunger and slight nausea.
• Dizziness and headache.
• Blurred vision.
• A fast heartbeat and feeling anxious.

These symptoms may go away shortly after you eat food that contains sugar.

Symptoms of moderate low blood sugar

If your blood sugar continues to drop (below 40 mg/dL), your behavior may change. Symptoms may include:

• Inability to concentrate.
• Confusion and irritability.
• Slurred speech.
• Unsteadiness when standing or walking.
• Muscle twitching.
• Personality changes, such as anger or crying.

Symptoms of severe low blood sugar

Symptoms of severe low blood sugar (usually below 20 mg/dL) include:

• Seizure.
• Loss of consciousness (coma).
• Stroke.
• Death.

Signs of low blood sugar at night

If your blood sugar drops while you are sleeping, your partner or other family members may notice that you are sweating and behaving differently. Signs of low blood sugar at night (nocturnal hypoglycemia) include:

• Restlessness.
• Making unusual noises.
• Attempting to get out of bed or accidentally rolling out of bed.
• Sleepwalking.
• Nightmares.
• Sweating.

You may wake up with a headache in the morning if your blood sugar was low during the night.

Signs of hypoglycemic unawareness

Some people have no symptoms of low blood sugar. The only symptom you may have is confusion. Or you may become unconscious before anyone realizes you have low blood sugar.

You may have hypoglycemic unawareness if you:

• Cannot tell by your symptoms that your blood sugar is low.
• Have low blood sugar several times a week.
• Have type 1 diabetes, or have had type 2 diabetes for a long time.

If you have hypoglycemic unawareness, test your blood sugar often, especially before activities like driving a car. Keep quick-sugar foods with you. If you take insulin, carry a glucagon emergency kit. You can also give friends and family instructions to treat low blood sugar.