Diabetes doesn’t suddenly appear. Before it officially "knocks on the door," your body has already sent out multiple warnings—but most people dismiss them as "I’ve just been too tired lately" or "it’s normal as I get older."
Below are 6 warning signs. If you experience even one, consider screening; if you experience two or more, please test your fasting blood glucose and HbA1c as soon as possible.
Signal 1: Increased thirst that drinking water can’t quench
This isn’t caused by hot weather or salty food. Rather, when blood glucose exceeds the kidneys’ reabsorption capacity (about 10 mmol/L), excess sugar drags water along as it’s excreted in urine. Dehydration triggers intense thirst signals. If you find yourself constantly reaching for water or waking up at night parched, it’s not simply "having internal heat."
Signal 2: Frequent urination, especially at night
Healthy people urinate 0–1 times per night. If you consistently get up to urinate more than twice at night over a stretch of time, and the amount is clearly increased, be vigilant. High blood glucose causes osmotic diuresis—one of the classic signs of diabetes.
Signal 3: Eating more but losing weight
Without intentionally dieting or increasing exercise, you lose more than 5% of your body weight within 1–3 months. This indicates insufficient insulin or insulin resistance—glucose can’t enter cells for energy, so the body breaks down fat and muscle instead. Muscle loss is one of the most dangerous signals in prediabetes: the less muscle you have, the harder it is to control blood sugar.
Signal 4: Wounds heal very slowly, and you have recurrent skin infections
High blood glucose weakens white blood cell function, lowering immunity. A minor scratch, a swollen gum, recurrent skin itching, or fungal infections—any of these could be signs that your blood glucose is already elevated.
Signal 5: Sudden blurred vision, like a fog in front of your eyes
High blood glucose changes the osmotic pressure of the lens in your eye, causing temporary refractive shifts. Many people think "my presbyopia has worsened," get new glasses but still can’t see clearly—only to discover the real issue when they check their blood sugar.
Signal 6: Intense drowsiness after meals, with lingering fatigue
In healthy people, blood glucose rises after a meal, and insulin quickly brings it back down. If insulin secretion is delayed or resistance is present, post-meal blood glucose stays high for a long time, disrupting the brain’s energy supply. This manifests as grogginess after eating and all-over weakness. It’s not laziness—it’s your metabolism sounding the alarm.
Who is most at risk?
- Direct family members with diabetes
- Abdominal obesity (waist circumference ≥90 cm in men, ≥85 cm in women)
- Chronic sleep deprivation or disrupted circadian rhythms
- Sedentary lifestyle with significantly low muscle mass
- History of gestational diabetes in women
- Co-occurring hypertension and hyperlipidemia
Simplest self-check you can do
If you belong to any of these groups and experience any of the above signals, do this: For three consecutive days, measure your fingertip blood glucose immediately after waking up and before eating. If on two of the three days the level is ≥6.1 mmol/L, or if any single reading is ≥7.0 mmol/L, go to the hospital for an oral glucose tolerance test (OGTT) and HbA1c test as soon as possible.
Early detection offers the best window for reversal
🔑 Golden Intervention Window
Prediabetes (fasting glucose 6.1–7.0, or post-meal 2-hour glucose 7.8–11.1 mmol/L) is the golden window for intervention. At this stage, pancreatic β-cell function still has significant recovery potential. Through a three-dimensional reversal strategy—building muscle, nourishing the liver, and regulating the pancreas—many people can bring their blood glucose back to normal and avoid lifelong medication.
⚠️ Important Note
This article is for health knowledge purposes only and does not constitute medical advice. Please refer to venous blood glucose tests from a hospital for accurate results. If you have concerns, consult a formal hospital’s endocrinology department.
