Frequent thirst, fatigue and blurry vision may signal type 2 diabetes

Dr. Luu Thuy Quynh from the Department of Endocrinology at Hanoi's Central Military Hospital 108, says type 2 diabetes often develops quietly.

Many people may live with the condition for years without obvious symptoms and are diagnosed only after complications affecting the heart, kidneys, eyes or nervous system have developed.

Early symptoms can be mild and non-specific, making them easy to overlook. Recognizing them can help people seek medical advice and identify blood sugar problems sooner.

Excessive thirst and frequent urination

Increased thirst and urination are among the best-known symptoms of diabetes, though they may be subtle in the early stages.

A person may simply find themselves drinking more water than usual, experiencing a dry mouth or waking once or twice during the night to urinate.

These changes are often blamed on hot weather, tea or coffee consumption, or aging. But when blood sugar remains high, excess glucose passes into the urine and draws water with it, increasing urine output. The resulting fluid loss then triggers greater thirst.

Persistent fatigue and low energy

Feeling unusually tired despite little physical exertion, struggling to concentrate, becoming sleepy during the day or experiencing a prolonged lack of energy can also be warning signs.

In people with insulin resistance, glucose builds up in the blood but cannot be efficiently used by cells for energy, leaving the body effectively short of fuel.

Because fatigue is common, many people attribute it to poor sleep, stress or work pressure rather than considering a blood sugar problem.

Unexplained weight changes

Type 2 diabetes may be associated with either weight loss or weight gain.

Some people gradually lose weight without trying because when cells cannot efficiently use glucose, the body begins breaking down fat and protein for energy.

Others gain weight, particularly around the abdomen. Insulin resistance causes the body to produce more insulin to compensate, which can encourage fat storage, especially visceral fat.

Because these changes often happen gradually, they may be mistaken for normal effects of aging or lifestyle.

Recurring infections and slow-healing wounds

Persistently high blood sugar can weaken the body's immune response and create favorable conditions for bacteria and fungi.

People may experience repeated skin infections, folliculitis, fungal infections of the skin or genital area, gingivitis or periodontitis. Small cuts and scratches may also take longer than usual to heal.

These problems are often treated separately without considering an underlying blood sugar disorder.

Temporary blurry vision

Some people with diabetes do not experience constant vision loss but instead notice episodes of blurry vision or difficulty focusing, particularly when reading, looking into the distance or late in the day.

High blood sugar can alter fluid levels inside the lens of the eye, temporarily affecting its ability to focus. Over time, persistent high blood sugar can also damage small blood vessels in the retina.

Because vision may shift between clear and blurry without causing pain, the symptom is often blamed on eye strain, aging or prolonged computer use.

Quynh stresses that type 2 diabetes can remain present for a long time without producing obvious symptoms.

The absence of noticeable warning signs therefore does not necessarily mean a person is free of the disease. Adults aged 30 and older, as well as people who are overweight or obese, physically inactive, have a family history of diabetes or other risk factors, should have their blood sugar checked periodically.

Early detection allows patients to manage blood sugar and related risk factors sooner, reducing the likelihood of cardiovascular, kidney, eye and neurological complications.