What is diabetes?

Rice, idli, dosa, bread, sweets and juice all turn into a sugar called glucose, which goes into your blood. It is your body's fuel. A hormone called insulin, made by the pancreas, works like a key: it lets that sugar move out of the blood and into cells in your muscles and liver.

When the key doesn't work properly, sugar stays in the blood and the level rises. That is diabetes.

Type 1: the pancreas stops making insulin. It usually starts young, and insulin injections are essential.
Type 2: the body still makes insulin but doesn't respond to it well. This is what most people in our community have, and it develops slowly over years.
Gestational diabetes: appears during pregnancy and raises the chance of type 2 later in life.

A "normal" sugar test can still hide a problem: insulin resistance

This is the part many people don't know. Type 2 diabetes doesn't arrive overnight. First, the body's cells stop responding properly to insulin, which is called insulin resistance. The pancreas makes up for it by pumping out more and more insulin, and that keeps blood sugar in the normal range.

So for years your sugar test can look normal while your insulin level is high. High insulin pushes the body to store fat, and weight goes up, especially around the belly. More weight makes the insulin resistance worse. Eventually the pancreas can't keep up, and sugar starts to rise: first to prediabetes, then to diabetes.

Signs to watch: fat building up around the waist; dark, thickened skin on the back of the neck or in the armpits; small skin tags on the neck; PCOS in women. Many people have no signs at all. An insulin blood test isn't a routine screening test, so ask your doctor whether it makes sense for you.

What does high blood sugar actually do?

The inner lining of your arteries (the endothelium) is like a smooth road. One doctor puts it simply: extra sugar in the blood acts like sandpaper, rubbing and damaging that inner lining over and over.

Just as dirt and rubbish collect in the potholes of a damaged pavement, "bad" LDL cholesterol particles and other material in the blood get stuck at the damaged spots. Over the years this build-up (plaque) grows, narrowing and stiffening the artery. If a plaque cracks, a blood clot forms on it and can block the artery completely: in the heart that's a heart attack, in the brain a stroke.

That's a simplified picture. In reality, high sugar also inflames the artery wall and sticks to proteins in it, making it stiff. High blood pressure, smoking and high LDL cholesterol damage the same lining, and together the risk multiplies.

Small blood vessels suffer too. That's why uncontrolled diabetes is a leading cause of blindness, kidney failure and nerve damage in the feet (numbness, sores that won't heal and, in the worst cases, amputation). South Asians tend to get diabetes younger and at a lower body weight.

Signs of high blood sugar

Constant thirst and passing urine often, including at night
Feeling tired all the time, or losing weight without trying
Blurred vision
Cuts that heal slowly, frequent infections
Numbness or tingling in the feet or hands

But many people have no symptoms for years, which is why testing matters.

Sugar that drops too low is dangerous too

If you take insulin or certain diabetes tablets (for example gliclazide or glimepiride), your sugar can fall too low (below 4.0 mmol/L or 70 mg/dL) if you skip or delay a meal, drink alcohol, or exercise more than usual.

Signs: shaking, sweating, a racing heart, sudden hunger, dizziness, confusion, irritability, slurred speech.

The "15-15" rule: take 15 grams of fast sugar right away, such as half a cup of juice or regular (not diet) soft drink, a tablespoon of sugar or honey, or 3–4 glucose tablets. Recheck after 15 minutes and repeat if you're still low. Once you're back up, have a small snack if your next meal is more than an hour away.

If the person is unconscious, don't put food or drink in their mouth (they could choke); call emergency services right away. If your sugar goes low often, tell your doctor, as your dose may need changing.

How you eat can bring the spikes down

A big plate of rice sends blood sugar up fast, and the body releases a lot of insulin to bring it back down. Feeling heavy and sleepy after a large rice meal is common and isn't by itself a sign of diabetes. But rather than lying down after eating, these changes help:

Vegetables first, then protein, rice last: greens, vegetables and salad first; then dal, egg, fish, chicken or curd; rice or roti at the end. In a small 2015 study in Diabetes Care, eating the same meal in this order left blood sugar about 37% lower an hour later than eating the carbohydrate first.
Split your plate: half vegetables, a quarter protein, and only a quarter rice or roti.
Walk after meals: a gentle 10–15 minute walk lowers the rise in sugar. Studies show even a few minutes of light walking beats sitting still.
Cut out drinks with sugar: juice, soft drinks and sweet tea or coffee raise sugar fastest. Eat whole fruit instead of juice.
Never stop medicines your doctor prescribed on your own. Food changes work together with them.

Who should get tested?

In Canada, Diabetes Canada recommends testing at least every 3 years from age 40. If you have risk factors (South Asian ancestry, a parent or sibling with diabetes, extra weight around the waist, high blood pressure or cholesterol, past gestational diabetes, sleep apnea), your doctor may test you earlier and more often. Ask what's right for you.

Test	Normal	Prediabetes	Diabetes
HbA1c (3-month average)	Below 6.0% (India/US: below 5.7%)	6.0–6.4% (India/US: 5.7–6.4%)	6.5% or higher
Fasting blood sugar	Below 6.1 mmol/L (110 mg/dL); India/US: below 100 mg/dL	6.1–6.9 mmol/L; India/US: 100–125 mg/dL	7.0 mmol/L (126 mg/dL) or higher
2-hour glucose test (OGTT)	Below 7.8 mmol/L (140 mg/dL)	7.8–11.0 mmol/L (140–199 mg/dL)	11.1 mmol/L (200 mg/dL) or higher

Canada mostly uses mmol/L; India and Sri Lanka mostly use mg/dL. One result alone isn't enough, and your doctor may repeat the test to confirm it. A home meter is for monitoring only; diagnosis needs a lab test.

It can be prevented

Not everyone with prediabetes goes on to get diabetes. Diabetes Canada says losing 5–10% of your body weight can make a major difference. At least 150 minutes a week of brisk walking (about 30 minutes a day), good sleep, stopping smoking, and a sleep apnea check if you snore loudly all help. If you have diabetes, keep an eye on your blood pressure and heart as well.

The bottom line

Don't assume you're fine: get tested. High sugar damages your blood vessels slowly and painlessly, and the harm shows up years later in the heart, brain, eyes, kidneys and feet. Eat your vegetables first, take a short walk after meals, and know your numbers.

Sources

Facts and prices checked on: 2026-10-31

Diabetes: what sugar in your blood really does

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