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Surprising Signs Your Blood Sugar is "Dangerously High"

Here’s what hyperglycemia feels like.
FACT CHECKED BY Emilia Paluszek

High blood sugar, or hyperglycemia, is a serious health condition most commonly associated with diabetes. "People with prediabetes do not process glucose efficiently, which leads to frequently high blood sugar build up due to a lack of insulin," says Trista Best MPH, RD, LD. "The body makes insulin to carry glucose into the cells and prevent this buildup, but when your body either isn't making enough or the cells become resistant to insulin, high glucose ensues." Here are five signs your blood sugar is out of control. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


What Is High Blood Sugar?

Abnormal high results of lipid profile and blood sugar test with blood sample tube

"In general, a blood sugar reading of more than 180 mg/dL or any reading above your target range is too high," advises Michigan Medicine. "A blood sugar reading of 300 mg/dL or more can be dangerous. If you have 2 readings in a row of 300 or more, call your doctor."



woman in bed feeling thirsty reaching for water

Constant thirst could be a sign of diabetes, experts say Amy Hess-Fischl, MS, RD, LDN, BC-ADM, CDCES, and Lisa M. Leontis RN, ANP-C. "No matter how much you drink, it feels like you're still dehydrated. Your tissues (such as your muscles) are, in fact, dehydrated when there's too much glucose (sugar) in your blood. Your body pulls fluid from the tissues to try to dilute the blood and counteract the high glucose, so your tissues will be dehydrated and send the message that you need to drink more. This is also associated with increased urination."


Constant Need to Pee

supermarket bathroom

Constantly needing to urinate could 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."


Extreme Hunger


"Even after you eat, you may still feel very hungry," say Hess-Fischl and Leontis. That's because your muscles aren't getting the energy they need from the food; your body's insulin resistance keeps glucose from entering the muscle and providing energy. Therefore, the muscles and other tissues send a 'hunger' message, trying to get more energy into the body."


High Blood Sugar and COVID-19

man unhealthy habits, tired at home, step debt

Diabetes has been shown to be a major risk factor for serious cases of COVID-19—studies show high blood sugar levels are correlated with worse health outcomes. "One main takeaway from this work is that the association between diabetes and COVID-19 outcomes is largely mediated by high inflammation in the body, as assessed by suPAR [a protein linked to kidney failure and heart disease] levels," says Alexi Vasbinder, PhD, RN. "According to the study, participants with diabetes had 20.7% higher suPAR levels than those without diabetes. However, the impact of hyperglycemia is independent of inflammation which means no matter what a patient's suPAR levels indicate, having high blood sugar levels or high insulin doses will also result in more serious COVID-19 illness."


How to Stay Safe Out There


Follow the public health fundamentals and help end this pandemic, no matter where you live—get vaccinated or boosted ASAP; if you live in an area with low vaccination rates, wear an N95 face mask, don't travel, social distance, avoid large crowds, don't go indoors with people you're not sheltering with (especially in bars), practice good hand hygiene, and to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.


Ferozan Mast
Ferozan Mast is a science, health and wellness writer with a passion for making science and research-backed information accessible to a general audience. Read more about Ferozan
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