Fastinghyperglycemia. This is blood sugar that's higher than 130 mg/dL (milligrams per deciliter) after not eating or drinking for at least 8 hours.
Postprandial or after-meal hyperglycemia. This is blood sugar that's higher than 180 mg/dL 2 hours after you eat. People without diabetes rarely have blood sugar levels over 140 mg/dL after a meal, unless it’s really large.
Frequent or ongoing high blood sugar can cause damage to your nerves, blood vessels, and organs. It can also lead to other serious conditions. People with type 1 diabetes are prone to a build-up of acids in the blood called ketoacidosis.
Diabetes is a serious disease that can cause debilitating nerve pain.
If you have type 2 diabetes or if you’re at risk for it, extremely high blood sugar can lead to a potentially deadly condition in which your body can’t process sugar. It's called hyperglycemic hyperosmolar nonketotic syndrome (HHNS). You’ll pee more often at first, and then less often later on, but your urine may become dark and you could get severely dehydrated.
It's important to treat symptoms of high blood sugar right away to help prevent complications.