
High blood sugar—known as hyperglycemia— is closely connected to diabetes and other serious health conditions, and can be dangerous if left untreated. "Keeping your blood glucose levels in the recommended ranges throughout the day will help you avoid long-term complications of diabetes, such as eye damage, heart attack (or other cardiovascular complications), kidney damage, nerve damage, stroke, problems with healing wounds… By maintaining your blood glucose levels—and avoiding hyperglycemia—you can reduce your risk of all these complications," says Amy Hess-Fischl, MS, RD, LDN, BC-ADM, CDCES. Here are five warning signs of high blood sugar, according to experts. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.
Frequent Urination

If you're feeling the need to use the bathroom more than usual, it might be a sign of high blood sugar. "The excess blood sugar molecules also 'spill' into the urine, meaning that as the blood filters through the kidneys, some of the sugar comes out of the blood and is not reabsorbed," says James Norman, MD, FACS, FACE. "The extra sugar which is now in the urine causes water molecules to follow (a normal physics principle) and therefore the person with diabetes urinates frequently (the second classic symptom of diabetes)."
Sexual Dysfunction

Did you know high blood sugar can cause erectile dysfunction? "It's easy to brush health warnings off, especially those related to conditions without symptoms, like early-stage diabetes. But what if I told you that getting your blood sugar under control could be the difference between having a healthy sex life and having trouble getting an erection at a very young age?" says urologist Nathan Starke, MD. "The reality is that diabetes and erectile dysfunction are intimately related. Poor blood sugar control can permanently ruin sexual function at a very early age."
Blurred Vision

Blurred vision can be a sign of high blood sugar and diabetes, and should not be ignored. "Over time, uncontrolled diabetes or chronic hyperglycemia can cause damage to the blood vessels throughout the body, including those in your eyes," says Dr. Russel Lazarus, B.Optom (Hons) M.Optom. "When the blood vessels in the retina become damaged, diabetic retinopathy, a serious eye disease, can develop. Diabetic retinopathy occurs when the retinal blood vessels leak blood and fluid into the retina, causing blurred vision and eventually leading to vision loss."
Constant Hunger

Constant hunger could be a sign your body is becoming insulin resistant. "If your body isn't making enough insulin—or any at all—or your cells resist your insulin, glucose can't get into the cells," says Mary Johnson, director of Diabetes Quality and Education at Geisinger. "That means you won't have energy and you can feel more tired and more hungry than usual."
Feeling Tired All the Time

Chronic fatigue is linked to a number of health conditions, but it's extremely common with high blood sugar. "High blood glucose can cause diabetes fatigue through inflammation," says David Spero, BSN, RN. "Blood vessels get inflamed by the sugar. When this happens, according to research, immune cells called monocytes come into the brain, causing fatigue."