High blood sugar (hyperglycemia) is one of the most common health issues in the United States, and one of the most overlooked. According to the CDC, about 1 in 3 US adults has prediabetes, and more than 8 in 10 of them do not know it. The early signs are easy to blame on age, a busy week or not drinking enough water. Here are the symptoms to know, what the numbers mean and what to do next.
Why blood sugar rises
After you eat, carbohydrates are broken down into glucose. Insulin, a hormone made by the pancreas, moves that glucose into your muscle, liver and fat cells to be used or stored. When cells respond less well to insulin (insulin resistance), or the pancreas cannot keep up, more glucose stays in the blood. The kidneys try to flush the extra out through urine, taking water with it — which explains many of the symptoms below.
10 high blood sugar symptoms in adults
- Increased thirstLosing more water through urine leaves you thirsty even when you drink regularly.
- Frequent urinationEspecially waking up at night to use the bathroom, as the kidneys clear extra glucose.
- FatigueGlucose is in the blood instead of inside the cells that need it for energy.
- Dry mouth and dry skinA sign of the fluid loss that comes with high glucose.
- Blurred visionHigh glucose can pull fluid into the lens of the eye and change how it focuses; it often improves when levels come down.
- HeadachesOften linked to dehydration and big swings in blood sugar.
- Feeling hungry soon after eatingWhen cells are short on fuel, the brain keeps asking for more.
- Slow-healing cuts and soresPersistently high glucose affects circulation and the immune response.
- Frequent infectionsIncluding skin, gum, urinary and yeast infections.
- Tingling in the hands or feetOver time, high glucose can affect the nerves; mention any numbness or tingling to your doctor.
Unexplained weight loss can also happen when glucose is lost in urine, and it is a reason to see a doctor promptly.
What the numbers mean
| Test | Normal | Prediabetes | Diabetes range |
|---|---|---|---|
| Fasting blood glucose | Under 100 mg/dL | 100–125 mg/dL | 126 mg/dL or higher |
| A1C (2–3 month average) | Under 5.7% | 5.7–6.4% | 6.5% or higher |
| 2 hours after a glucose drink | Under 140 mg/dL | 140–199 mg/dL | 200 mg/dL or higher |
Diagnostic ranges from the American Diabetes Association. A diagnosis requires a doctor and usually two tests. New to the A1C number? Read A1C levels explained.
Warning signs that need urgent care
Do not wait on these
Very high readings together with nausea or vomiting, deep or rapid breathing, fruity-smelling breath, confusion, extreme drowsiness or severe dehydration need urgent medical attention. If you take insulin or other glucose-lowering medication, follow the plan your care team gave you.
Common everyday triggers
- Sugary drinks and large portions of refined carbs — the fastest way to spike glucose.
- Sitting for long stretches — inactive muscles take up less glucose.
- Stress and poor sleep — cortisol and adrenaline release stored glucose from the liver.
- Illness — a cold or infection can raise readings for several days.
- Some medications — such as steroids; never stop a medication without talking to your doctor.
What to do next
- Get testedAsk your doctor for a fasting glucose or A1C test, especially if you are over 35, carry weight around the waist or have a family history.
- Fix the drinks firstWater, unsweetened tea and black coffee instead of soda, juice and sweet coffee drinks. Our 7-day sugar reset plan walks you through it.
- Build a steadier plateHalf vegetables, a palm of protein, a fist of slow carbs and some healthy fat.
- Walk after meals10–15 minutes after lunch and dinner is one of the most effective habits there is.
- Protect sleep and manage stress7–9 hours, a regular bedtime and a few minutes of slow breathing daily.
Our recommendation: Sugar Reset
Alongside those habits, Sugar Reset is the daily support we recommend for adults who want to keep blood sugar in a healthy range. Sugar Reset is a liquid formula with chromium picolinate — the mineral that helps insulin move glucose into your cells — plus a 22-ingredient blend of gymnema leaf, African mango seed, green tea, maca, Panax ginseng and amino acids. One or two droppers each morning, made in the USA in an FDA-registered facility, with no added sugar. It is built to support balanced blood sugar, healthy insulin function and steady energy, the exact areas behind most of the symptoms above.
The best value is the 6-bottle package at $49 per bottle ($294, free shipping); 3 bottles are $69 each ($207, free shipping) and 2 bottles $79 each. One-time payment, no subscription, 60-day money-back guarantee. Sugar Reset supports healthy blood sugar; it does not replace medical care. If you have symptoms, see your doctor, and if you take medication, show them the label first.
Ready to support steadier numbers every day? Get Sugar Reset from the official site.
Frequently asked questions
What are the first signs of high blood sugar?
The earliest signs are usually increased thirst, needing to urinate more often (including at night), tiredness and dry mouth. Many adults with slightly high blood sugar have no symptoms at all, which is why a simple blood test is the only way to know for sure.
What blood sugar level is too high?
Per the American Diabetes Association, a fasting level of 100–125 mg/dL is in the prediabetes range and 126 mg/dL or higher on two tests suggests diabetes. Two hours after eating, readings under 140 mg/dL are considered normal for people without diabetes. Your doctor interprets your own numbers.
When is high blood sugar an emergency?
Seek urgent care for very high readings with vomiting, deep or rapid breathing, fruity-smelling breath, confusion, extreme drowsiness or signs of dehydration. These can signal dangerous conditions that need treatment right away.
Can stress or poor sleep raise blood sugar?
Yes. Stress hormones such as cortisol and adrenaline tell the liver to release stored glucose, and even a few nights of short sleep make the body less sensitive to insulin. Both can push readings up without any change in diet.
This article is for general information only and is not medical advice. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Talk to your doctor before changing your diet, exercise or supplements, especially if you take medication.