Diabetes and Prediabetes Symptoms: How to Recognize Them Early

Type 2 diabetes is one of the most common chronic conditions worldwide. According to the WHO, around 422 million people have it — and approximately half of them don't know. The disease is insidious because in its early stages it produces almost no symptoms, and by the time they become noticeable, complications have often already begun. This article covers the early signs of diabetes, what prediabetes means, and how to check your blood sugar.

Early signs of type 2 diabetes that are easy to miss

Type 2 diabetes develops slowly. The earliest symptoms are so mild and non-specific that most people attribute them to tiredness, stress, or ageing. Here's what to watch for:

Persistent thirst and dry mouth. High blood glucose draws water from tissues — the body tries to dilute the blood and flush excess sugar through the kidneys.
Frequent urination, including at night. The kidneys work overtime filtering sugar-laden blood, expelling it with large amounts of water.
Fatigue after meals, especially carbohydrate-heavy ones. Cells can't use glucose effectively due to insulin resistance — so despite high blood sugar, there isn't enough energy.
Slow healing of wounds and cuts. High sugar impairs immune function and reduces circulation in small blood vessels.
Frequent infections — especially urinary tract, skin, and gum infections. Bacteria and fungi thrive in a glucose-rich environment.
Itchy skin and genitals — a result of dryness and fungal infections.
Blurred vision — osmotic pressure changes cause the lens to shift shape, temporarily affecting vision.
Numbness or tingling in the feet and hands — an early sign of diabetic neuropathy, nerve damage from elevated glucose.

If you notice several of these symptoms, this is a reason to get a blood glucose test and see a doctor without delay.

Prediabetes: what it is and what to do

Prediabetes is an intermediate state: blood sugar is above normal but hasn't reached the diabetes threshold. Research shows that people with prediabetes develop type 2 diabetes at a rate of 5–10% per year — but this risk can be cut by more than half with lifestyle changes.

Reference values:

Fasting plasma glucose: normal — below 5.6 mmol/L (100 mg/dL); prediabetes — 5.6–6.9 mmol/L; diabetes — 7.0 mmol/L and above.
HbA1c: normal — below 5.7%; prediabetes — 5.7–6.4%; diabetes — 6.5% and above.
2-hour glucose after oral glucose tolerance test (OGTT): prediabetes — 7.8–11.0 mmol/L; diabetes — 11.1 mmol/L and above.

Prediabetes generally causes no noticeable symptoms. It is found incidentally or through targeted screening. High-risk groups who should be screened every 1–3 years:

overweight or obesity (BMI above 25);
sedentary lifestyle;
parent or close relative with diabetes;
high blood pressure (above 130/80 mmHg);
history of gestational diabetes;
polycystic ovary syndrome (PCOS);
age 45 or over.

What actually works for prediabetes: losing 5–7% of body weight (if overweight), at least 150 minutes of moderate exercise per week, and cutting back on fast carbohydrates and sugary drinks. Lifestyle changes alone — without medication — can fully normalise blood sugar levels.

Symptoms of hypoglycaemia (low blood sugar)

Hypoglycaemia is a rapid drop in blood glucose below 3.9 mmol/L (70 mg/dL). It most often occurs in people with diabetes taking insulin or glucose-lowering medications. It can also happen in healthy people — during prolonged fasting, intense exercise, or excess alcohol intake.

Symptoms of hypoglycaemia:

sudden weakness and shaking hands;
sweating (cold sweat);
rapid heartbeat;
dizziness and headache;
intense hunger;
irritability or sudden mood shift;
difficulty concentrating, confusion;
in severe hypoglycaemia — loss of consciousness.

First aid: 15–20 g of fast carbohydrates — a glass of juice or sugary drink, 3–4 glucose tablets, a few sweets. Recheck blood sugar after 15 minutes. If consciousness is impaired — call emergency services.

Tests for diagnosing diabetes

Key lab markers and their reference ranges:

Fasting plasma glucose (at least 8 hours without food): normal — below 5.6 mmol/L (100 mg/dL). Simple, inexpensive, and available at any lab.
HbA1c (glycated haemoglobin): normal — below 5.7%. Reflects average blood sugar over the past 2–3 months. No fasting required. Convenient for monitoring in people with established diabetes (target usually below 7%).
Oral glucose tolerance test (OGTT): blood glucose measured before and 2 hours after drinking 75 g of glucose. Detects hidden impairment in glucose metabolism.
Urine glucose: normally absent. Its presence indicates very high blood glucose levels.
Insulin and HOMA-IR index: assess insulin resistance before overt glucose abnormalities appear. Ordered by a GP or endocrinologist when metabolic syndrome is suspected.

Managing diabetes at home

If diabetes has already been diagnosed, home monitoring of blood sugar is an essential part of care.

Glucometer. A compact device that measures blood sugar from a fingertip blood drop. How often to test depends on your type of diabetes and treatment — ask your doctor.

Continuous glucose monitoring (CGM). A sensor worn on the skin that measures glucose every few minutes. Far more convenient than repeated finger pricks, and it shows trends — allowing you to respond before hypoglycaemia occurs.

Food and activity diary. Helps identify which foods and situations spike your blood sugar the most — everyone's response is different.

Not sure which specialist to see? Try describing your symptoms to the assistant — or use the doctor routing tool to find out whether you need an endocrinologist or a GP will do.

Frequently asked questions

What is the difference between type 1 and type 2 diabetes?

In type 1 diabetes, the immune system destroys the insulin-producing cells of the pancreas — so there is no insulin. It typically begins in childhood or young adulthood and requires insulin therapy. In type 2 diabetes, insulin is produced but cells don't respond to it properly (insulin resistance). It develops in adults and is closely linked to lifestyle and excess weight.

Can type 2 diabetes be reversed?

Not "cured" in the strict sense — but remission (normal blood sugar without medication) is genuinely achievable. This is done through 10–15% weight loss, dietary change, and regular exercise. Some people maintain normal blood sugar without medication for years.

How dangerous is high blood pressure in diabetes?

Combining diabetes and hypertension sharply increases the risk of heart attack, stroke, kidney disease, and vision loss. The target blood pressure in diabetes is below 130/80 mmHg. Managing blood pressure matters as much as managing blood sugar.

Can people with diabetes eat fruit?

Yes, but thoughtfully. Fruit contains fibre and nutrients, but also fast carbohydrates. Berries, apples, and pears with a moderate glycaemic index are better choices. Juices — even freshly squeezed — raise blood sugar quickly and are best limited.

What is gestational diabetes?

Gestational diabetes is elevated blood sugar that first appears during pregnancy. It usually resolves after delivery, but women who have had it face a 7–10 times higher risk of developing type 2 diabetes later in life. Blood sugar monitoring during pregnancy is essential.

Must people with diabetes cut out all sugar?

Complete elimination isn't necessary, but sugar must be carefully limited. Current guidelines focus on restricting added sugar, not imposing a total ban. Variety in the diet and control of overall carbohydrate intake matter more than rigid prohibitions.

Symptomatica is an informational reference service. Not a medical service; does not diagnose or prescribe treatment. For any symptoms, please consult a doctor.

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