Hypoglycemia: 10 Signs of Low Blood Sugar

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The term "hypoglycemia" means low blood sugar. By definition, hypoglycemia is a glucose level ≤ 70 mg/dl (3.9mmol/L). There are several common causes of low blood sugar in people with diabetes:

Let's look at the signs and symptoms of hypoglycemia.


You feel suddenly weak, shaky, or lightheaded

If you suddenly feel weak, shaky, or lightheaded—or you even faint–you could be experiencing these common signs of hypoglycemia. A headache that comes on quickly, weakness or tremor in your arms or legs, and a slight trembling of your body are also signs that your blood sugar is too low.


You're pale, clammy, and/or you break out in a sweat

When you are experiencing hypoglycemia, you may have clammy, visibly pale skin, and break out in a cold sweat, even when you're not overheated. When your blood sugar is too low, the body’s fight or flight response is triggered, and adrenaline is released. The extra adrenaline is the cause of the excess sweating.


Your heart is pounding or racing

The extra adrenaline released during hypoglycemia can cause your heart to pound and your pulse to race. You may also notice you are having heart palpitations—irregular changes in your heart rhythm. Dizziness may also accompany these heart-related symptoms.


You feel hungry or nauseated

Hypoglycemia can trigger a feeling of extreme hunger, nausea, and even vomiting. Traditionally, eating a corrective dose of something with sugar can help restore blood sugar levels to a more normal level. Pure glucose is the preferred treatment, but any form of carbohydrate that contains glucose will raise blood glucose.

Sample treatments:

  • 4 glucose tablets or one tube of glucose gel
  • 1/2 cup (4 ounces) of fruit juice—not low-calorie or reduced sugar (except people with kidney disease)
  • 1/2 can (4 to 6 ounces) of soda—not low-calorie or reduced sugar
  • 1 tablespoon of sugar, honey, or corn syrup
  • 2 tablespoons of raisins


You feel overwhelmed, anxious or irritable

Beyond physical symptoms, hypoglycemia can cause signs of emotional instability. You may feel suddenly overwhelmed, frustrated, angry, anxious, or irritated, or in some cases, irrational. You may even burst into tears for no apparent reason.


You feel suddenly tired or sleepy

If you suddenly feel tired, or overwhelmingly sleepy, this can be a sign that your blood sugar is low, and your body is not getting enough energy in the form of glucose. Rather than taking a nap–and the risk that your hypoglycemia episode will worsen–it's essential to treat and monitor your blood glucose.


You have a sudden change in vision

When your brain doesn't get enough glucose, the ability to manage vision deteriorates. When your blood sugar is low, you may notice that your vision rapidly becomes blurry, or you may have other visual disturbances, such as double vision, tunnel vision, or enlarged pupils.


You're feeling 'out of it'

When your blood sugar is low, it can make you feel spacey or mentally confused. You may find it hard to follow a conversation. Others may find it hard to make sense of what you're saying, and your speech may be slurred. These are potential signs that your blood sugar has become dangerously low.


You have numbness and tingling in your mouth and lips

One of the signs of low blood sugar is a feeling of numbness and a tingling sensation in your mouth and/or lips. This is your body's nervous system responding to the hypoglycemia and is considered a sign that your blood sugar has become dangerously low.


You pass out, or become unresponsive

When your blood sugar goes dangerously low, you may pass out, or become unresponsive. In some cases of hypoglycemia, failing to resolve the low blood sugar can result in coma. In this situation, you need immediate medical attention.


Treating hypoglycemia

When you have diabetes, you should carry–or have immediate access to–a source of fast-acting carbohydrates such as glucose tablets, glucose gel, hard candy, juice, or soda, to counteract and treat any episodes of hypoglycemia.

If you tend to pass out during episodes of dangerously low blood sugar, you should have access at all times to a glucagon emergency kit, and the people around you should be trained how to use it.