Early Symptoms of Diabetes: 12 Warning Signs, Risk Factors and When to Get Tested

Diabetes is a condition in which the level of sugar (glucose) in the blood stays too high. In type 2 diabetes, which makes up the great majority of cases, the problem develops slowly. Many people feel well for years while high sugar quietly damages the eyes, kidneys, nerves and heart. In type 1 diabetes, symptoms usually appear over days or weeks and can become severe quickly. Recognising the early signs allows earlier treatment and fewer complications.

12 early warning signs of diabetes

1. Increased thirst. Extra sugar in the blood pulls water out of the body, leaving you constantly thirsty.
2. Frequent urination. The kidneys try to remove extra sugar through urine. Waking several times at night to pass urine is a typical clue.
3. Unexplained tiredness. Cells cannot use sugar properly for energy, so you feel drained.
4. Increased hunger, even soon after eating.
5. Unexplained weight loss, especially with type 1 diabetes or advanced type 2, as the body burns fat and muscle for energy.
6. Blurred vision. High sugar can swell the lens of the eye. It often improves when sugar is controlled, but untreated diabetes can permanently damage the retina.
7. Slow-healing cuts, sores or infections, particularly on the feet.
8. Frequent infections: recurrent skin boils, urinary infections, gum disease, or fungal infections such as thrush or athlete's foot.
9. Tingling, burning or numbness in hands or feet, caused by nerve damage.
10. Dark, velvety patches of skin on the neck, armpits or groin (acanthosis nigricans), a sign of insulin resistance. Skin tags may also be more common.
11. Dry, itchy skin, especially around the genital area.
12. Mood changes and irritability, from fluctuating sugar and poor sleep.

Having one or two of these does not mean you have diabetes, but together or persistent they deserve a blood test.

Symptoms in women

Women may notice recurrent vaginal thrush or urinary infections, irregular periods or PCOS, and a history of gestational diabetes or a large baby. Women with PCOS and gestational diabetes have a much higher lifetime risk of type 2 diabetes and need regular screening.

Symptoms in men

Men may notice erectile dysfunction, reduced stamina, infections of the foreskin or glans, and low testosterone symptoms. Many men ignore early symptoms and present late with complications such as heart disease, foot ulcers or kidney problems.

Symptoms in children and teenagers

In type 1 diabetes, parents may notice excessive thirst, bedwetting in a previously dry child, weight loss, tiredness and irritability. Abdominal pain, vomiting, fast deep breathing, and drowsiness may signal diabetic ketoacidosis, an emergency requiring immediate hospital care. Type 2 diabetes is also appearing in overweight children and teens, often with dark neck skin and a family history. Learn the differences in our guide to type 1 and type 2 diabetes.

Risk factors for type 2 diabetes

• Age over 30-35 (earlier in South Asians)
• Overweight or a BMI of 23 or more, or a large waist (men 90 cm or above, women 80 cm or above)
• Family history of diabetes in a parent or sibling
• Physical inactivity and diet high in sugar and refined starch
• High blood pressure or abnormal cholesterol
• Polycystic ovary syndrome, or previous gestational diabetes
• Fatty liver disease
• Previously found prediabetes
• Long-term steroid use and some other medicines

Use our BMI calculator to check where you stand, and read why Asian BMI cutoffs are lower.

Which tests to ask for

• Fasting plasma glucose: diabetes at 126 mg/dL (7.0 mmol/L) or above; prediabetes 100-125 mg/dL (5.6-6.9 mmol/L).
• HbA1c: diabetes at 6.5% or above; prediabetes 5.7-6.4%. Use our HbA1c calculator to understand the result.
• Oral glucose tolerance test: a 2-hour value of 200 mg/dL (11.1 mmol/L) or more indicates diabetes.
• Random glucose of 200 mg/dL or higher with symptoms.

See the full normal blood sugar ranges for adults, pregnancy and children. A single abnormal result without symptoms should be confirmed by a second test.

What to do if you notice symptoms

1. Book a blood test with your doctor within a few days. Do not rely on home-based urine strips alone.
2. Do not start herbal or "sugar-lowering" products to mask the problem before testing. They can delay diagnosis.
3. Bring information: family history, weight changes, medicines, and symptoms with dates.
4. If diagnosed, ask about your HbA1c target, diet and exercise plan, medicines, and a baseline check of eyes, kidneys, feet, blood pressure and cholesterol.

Emergency symptoms

Go to hospital immediately for vomiting, severe abdominal pain, fruity-smelling breath, deep fast breathing, confusion or drowsiness in someone with high sugar. In people who have diabetes already, a blood sugar below 54 mg/dL (3.0 mmol/L), or low sugar with confusion or fits, is also an emergency.

Preventing type 2 diabetes

Prevention works. Studies show that losing 5-7% of weight and walking about 150 minutes a week cut the risk of developing diabetes by more than half in people with prediabetes. Eat plenty of vegetables, pulses and fish, limit sugary drinks and sweets, keep rice and bread portions moderate, sleep well and avoid smoking. Our diabetic diet guide for Sri Lanka has practical meal ideas, and you can read whether diabetes can be reversed or cured.

When to see a doctor

See a doctor if you have any of the symptoms above for more than a week or two, if you have several risk factors and have never been tested, or if you are pregnant or planning pregnancy with risk factors. Everyone aged 30-35 or older should be tested at least every three years, or yearly if they have prediabetes or high risk.

References

• American Diabetes Association: Standards of Care in Diabetes, classification, diagnosis and screening
• World Health Organization: diabetes fact sheet
• International Diabetes Federation: Diabetes Atlas
• Diabetes Prevention Program Research Group, New England Journal of Medicine