Fatigue, thirst and blurred vision: early signs that may signal type 2 diabetes

Type 2 diabetes often develops slowly and is frequently missed because early signs are mistaken for stress, tiredness or normal ageing. The body sends multiple subtle signals — and recognising them early can speed diagnosis and treatment.

The most overlooked early symptom is persistent, deep fatigue: not the tiredness after a hard day, but a prolonged exhaustion lasting weeks or months that does not resolve after rest and is often accompanied by problems concentrating. The explanation is physiological: when blood glucose is high the glucose stays in the bloodstream instead of entering cells to be used as fuel, so the body is effectively starved of energy despite excess sugar in the blood.

In parallel, increased thirst and frequent urination — especially at night — are typical. When glucose is elevated the kidneys expel more fluid to remove the excess sugar, causing dehydration; people may wake at night to drink water or use the toilet and attribute it to the cold, drinking more fluids, or age. When thirst, dry mouth and frequent urination appear together, clinicians consider this combination typical for early diabetes.

Other warning signs to watch for

High glucose can also affect vision: excess blood sugar pulls fluid from the eye’s lens, temporarily changing its shape and causing blurred sight. Difficulties focusing and daily fluctuations in vision are often blamed on long hours at a computer or dry eyes, but vision usually returns to normal once glucose is controlled.

Additional signals include increased appetite shortly after eating, slow wound healing, dry itchy skin (often on the legs), and tingling, burning or numbness in the fingers and toes. Elevated blood sugar damages small blood vessels and nerves, which explains both delayed healing and early neuropathic symptoms. Some people also lose weight without trying because cells cannot use glucose and the body burns fat and muscle instead. Recurrent fungal and bacterial infections are another clue, since high glucose promotes microbial growth.

If you notice two or more of these symptoms, laboratory testing is the next step: fasting plasma glucose and HbA1c, which shows average blood sugar over the last three months. Fasting glucose under 5,6 mmol/L is considered normal, 5,6–6,9 mmol/L indicates prediabetes, and 7,0 mmol/L or higher is diagnostic for diabetes. For HbA1c, the cutoffs are 5,7 and 6,4 percent for prediabetes and 6,5 percent or more for diabetes; elevated results are usually confirmed by repeat testing.

While awaiting a doctor’s assessment, simple lifestyle changes help: cut back on refined sugar, sweetened drinks and white bread, drink more water and increase physical activity; even a short walk after a meal can stabilise blood sugar. These measures do not replace medical evaluation, but they can ease symptoms and reduce strain on the body.

There are situations that require urgent care: marked weakness, dizziness, rapid breathing, extreme thirst, vomiting, profound sleepiness or confusion may signal severe hyperglycaemia and need immediate medical attention. For people with normal findings and no risk factors, screening is recommended every two to three years; annual checks for prediabetes and tests every three to six months for confirmed diabetes are advised depending on clinical judgement. Early therapy and lifestyle change significantly lower the risk of later complications affecting blood vessels, nerves, kidneys and sight.

Photo: Unsplah