Hyperglycemia is when you have elevated blood sugar. Before a meal, or when you have not eaten in several hours, high blood sugar is defined as 130 mg/dL. Two hours after eating, hyperglycemia is when blood sugar levels are above 180 mg/dL.
By comparison, normal blood sugar levels are generally between 80 mg/dL and 130 mg/dL. Hyperglycemia is most common for people with diabetes, and essentially, it describes the high blood sugars that define the chronic condition.
In some cases, hyperglycemia can also occur as a result of stress or as a side effect of steroid medication. Here’s how you can recognize the signs of high blood sugar and lower it quickly.
Signs and symptoms
The most common symptoms of hyperglycemia include:
- Increased thirst
- Drinking liquids more frequently
- Urinating more frequently
- Blurry vision
- Weight loss
However, the only way to know for sure if you have hyperglycemia is with a blood draw, says Jordan Messler, MD, a hospitalist at Morton Plant Hospitalist group in Clearwater, Florida. This can confirm that your blood sugar levels are elevated, and by how much. In fact, symptoms often won’t become severe until blood sugars rise above 200 mg/dL.
If left untreated, hyperglycemia can lead to diabetic ketoacidosis (DKA) within 24 hours in some cases. This condition, most common in people with type 1 diabetes, occurs when the body is not able to break down sugar properly for fuel, so it breaks down fats instead, Messler says. This naturally releases acids into the blood, and because the body cannot flush the acid quickly enough, it becomes toxic in the blood.
DKA is a medical emergency, and people with the following symptoms should visit the emergency room, especially if they have diabetes, Messler says:
- Shortness of breath
- Dry mouth
- Abdominal pain
Both type 1 and type 2 diabetes can cause hyperglycemia. But there are also other potential causes, like stress or steroid medications.
People with diabetes are not able to process blood sugar effectively, either because they do not produce insulin, the hormone that breaks down blood sugar (type 1), or because their body does not utilize insulin effectively (type 2).
Since the body cannot break down blood sugar, it builds in the bloodstream and is more likely to cause high blood glucose levels, or hyperglycemia.
Hyperglycemia can also occur occasionally in people who are being treated for diabetes. These spikes in blood sugar levels can be caused by:
- Eating too much
- Not exercising enough
- Giving yourself too little insulin or medication
- The dawn phenomenon, or a surge in hormones during the early morning that can spike blood sugar
- Stress or illness