Type 2 Diabetes, Explained

What happens

• Insulin works like a key that lets glucose (sugar) from your food into your cells for energy.
• In type 2 diabetes, cells respond less well to insulin, and over time the pancreas can't keep up.
• Prediabetes and early type 2 diabetes often cause no symptoms, so a simple blood test is the way to find them.
• Over years, high blood sugar damages blood vessels and nerves, raising the risk of heart attack, stroke, and kidney, eye and foot problems.
• Modest changes work: in a large study, people with prediabetes cut their risk of type 2 diabetes by 58%.

What you can do

• Ask your health care provider about an A1C or fasting blood sugar test if you're over about 40 or have risk factors.
• Aim for about 150 minutes of brisk activity a week; short walks count.
• If your provider suggests it, losing a modest amount of weight (about 5–7%) can lower your risk.
• Fill your plate with vegetables, beans, whole grains and other high-fibre foods.
• Swap sugary drinks for water.
• If you smoke, get help to quit.

Common questions

Does eating sugar cause type 2 diabetes?

Not directly. Type 2 diabetes comes from a mix of genes, age, weight and activity. But sugary drinks do raise the risk, so cutting back on them is a good idea.

What are the early signs of type 2 diabetes?

Often there are none for years. When symptoms do appear, they can include feeling very thirsty, peeing more often, feeling tired, and blurry vision. A blood test is the only way to know for sure.

Can prediabetes be reversed?

Often, yes. In the Diabetes Prevention Program, adults with prediabetes who aimed to lose about 7% of their body weight and be active about 150 minutes a week lowered their risk of type 2 diabetes by 58%.

Transcript

Every time you eat, your body breaks down much of your food into a simple sugar called glucose. It's the fuel that powers the cells all through your body.

But that fuel only helps once it gets inside your cells. When that process slowly stops working, the result can be type 2 diabetes. Let's see how it happens, and how to lower your risk.

After a meal, glucose passes from your gut into your bloodstream, and the level of sugar in your blood begins to rise.

Your pancreas, an organ tucked behind your stomach, senses that rise. Special cells inside it release a hormone called insulin.

Insulin works like a key. It unlocks your cells, so glucose can move in from the blood and be used for energy.

As glucose moves into the cells, your blood sugar falls back to its normal range. In a healthy body, this happens after every meal, without you noticing.

In type 2 diabetes, the locks get stiff. Cells in your muscles, liver and fat stop responding as well to insulin. This is called insulin resistance.

At first, the pancreas makes up for it by working harder, pumping out more and more insulin to keep blood sugar in range.

But over the years, the insulin-making cells can wear out and fall behind. Blood sugar starts to creep up.

When blood sugar is higher than normal, but not yet high enough to be diabetes, it's called prediabetes. And prediabetes can often be turned around.

If blood sugar keeps climbing, it becomes type 2 diabetes. It's by far the most common kind. About nine in ten people with diabetes have type 2.

So why does high blood sugar matter? Over many years, extra sugar in the blood damages the walls of blood vessels, large and small, and the nerves they feed.

That's how diabetes raises the risk of heart attack and stroke. It can also harm the kidneys, the eyes, and the feet, where numb nerves and poor circulation can let small sores go unnoticed.

Here's the tricky part. Type 2 diabetes often causes no symptoms at all for years. Most people with prediabetes don't know they have it.

When symptoms do appear, they can include feeling very thirsty, peeing more often, feeling tired, and blurry vision.

That's why testing matters. A simple blood test, like an A1C, which shows your average blood sugar over the past few months, or a fasting blood sugar test, can find it early.

Ask your health care provider about testing if you're over about forty, or if you have risk factors, such as a parent or sibling with diabetes, extra weight, high blood pressure, or diabetes during a pregnancy.

Now for the good news. In a large study called the Diabetes Prevention Program, adults with prediabetes made modest, everyday changes.

They aimed to lose about seven percent of their body weight, and to be active for about a hundred and fifty minutes a week. Their risk of getting type 2 diabetes fell by fifty-eight percent.

That's about twenty minutes of brisk walking a day, and short walks count too. Every bit of activity helps your muscles use glucose.

On your plate, choose more vegetables, beans, whole grains and other high-fibre foods, and swap sugary drinks for water. And if you smoke, quitting lowers your risk too.

If you do have type 2 diabetes, it can be managed well. Healthy habits are the foundation, and many people also take medicine, such as metformin. Some need insulin.

Needing insulin isn't a failure. Type 2 diabetes often changes over time. Regular checks of your eyes, feet and kidneys help catch problems early.

One common myth is that eating sugar causes diabetes. It's not that simple. Type 2 comes from a mix of genes, age, weight and activity. But sugary drinks do raise the risk, so they're worth cutting back.

So, to recap. Insulin is the key. Resistance makes the pancreas work harder. High blood sugar harms vessels and nerves. And small, steady changes lower your risk.

Now you know how type 2 diabetes develops, and how to lower your risk. Ask about a simple blood test. Knowing your numbers is a great first step.

Sources

1. CDC — Diabetes Basics
2. NIDDK — Insulin Resistance & Prediabetes
3. NIDDK — Diabetes Prevention Program (DPP)
4. CDC — Diabetes Symptoms
5. CDC — Diabetes Testing
6. WHO — Diabetes fact sheet
7. Diabetes Canada — Clinical Practice Guidelines