You can have diabetes and still feel perfectly well. This guide explains what diabetes is, what the different types are, and which article to read next.
About 9.1% of Singapore residents aged 18 to 74 have diabetes. That works out to roughly one adult in 11. The rate was 9.5% in 2019 to 2020, so it has stayed about the same.[1]
The Understand Health team wrote this guide as the starting point for our diabetes articles. The other articles cover symptoms, food, and emergencies, and they make more sense once you know what diabetes actually is. So we begin there.
What Is Diabetes?
Diabetes is a disease in which the sugar in your blood stays too high. The medical name for this sugar is glucose. To see why it goes wrong, it helps to follow what happens to your food.
- You eat. Rice, noodles, bread, fruit, and sweet drinks all contain carbohydrates. Your body breaks them down into glucose, which enters your blood.
- Your cells need the glucose. Cells are the tiny building blocks that make up your body. They use glucose for energy, but they cannot take it in from the blood on their own.
- Insulin lets the glucose in. Insulin is a hormone, which is a chemical messenger made inside your body. It is made by an organ called the pancreas, which sits near your stomach. You can think of insulin as a key that opens the door of each cell so glucose can go inside.[2]
- In diabetes, this system stops working. Either your body does not make enough insulin, or it cannot use its insulin properly. The glucose has no way into the cells, so it stays in your blood and builds up.[2]
The result is a high blood sugar level. This matters because too much glucose in the blood can slowly damage your blood vessels and nerves. Blood vessels are the tubes that carry blood around your body. Nerves carry signals between your brain and the rest of your body. Over time, this damage can harm your heart, eyes, kidneys, and feet.[2][3]
The Main Types of Diabetes
There are several types. They differ in why the body’s insulin system stops working.
Type 2 diabetes is by far the most common. More than 95 out of every 100 people with diabetes have this type.[3] In type 2, your body does not make enough insulin, or it cannot use its own insulin properly. Doctors sometimes say the body has become “resistant” to insulin. This means the key no longer opens the door as well as it should.[2]
Type 2 can start at any age, even in childhood.[2] It often causes mild symptoms or none at all, which is one reason it goes unnoticed.[3] The risk factors listed on HealthHub include:[4]
- A parent, brother, or sister with diabetes
- Having had diabetes during pregnancy
- Being 40 or older
- A BMI of 23.0 or higher. BMI stands for body mass index, a number worked out from your height and weight. It is used to check whether your weight is healthy for your height.
- Not being physically active
- Unhealthy eating habits
Type 1 diabetes is a different condition. It is an autoimmune condition. Your immune system is the body’s defence against germs. In an autoimmune condition, the immune system attacks a part of your own body by mistake. In type 1, it destroys the cells in the pancreas that make insulin.[4] The body then makes little or no insulin.
Type 1 is not caused by diet or lifestyle.[4] It usually starts in childhood or early adulthood, but it can appear at other ages.[4] People with type 1 need insulin injections to stay alive.[3]
Gestational diabetes happens during pregnancy. Blood sugar levels usually return to normal after the baby is born. However, having it raises your risk of developing diabetes later in life.[4]
Pre-diabetes is not a type of diabetes. It is a warning stage, when your blood sugar is higher than normal but not yet high enough to count as diabetes. It usually causes no symptoms, so only a blood test can find it.[4] Almost everyone who develops type 2 diabetes passes through pre-diabetes first.[5]
Pre-diabetes is not rare here. In 2017, MOH estimated that about 430,000 Singaporeans aged 18 to 69, or 14%, had it. That figure is several years old. MOH also said that, without any change, one in three people with pre-diabetes is likely to develop type 2 diabetes within eight years. Changes to daily habits, such as eating and exercise, can slow that progress and in some cases reverse it.[6]
How Diabetes Is Diagnosed in Singapore
Diabetes is diagnosed with a blood test. Blood sugar is measured in a unit called mmol/L. The table below shows the ranges used on HealthHub.[5]
| Test | Normal | Pre-diabetes | Diabetes |
|---|---|---|---|
| Fasting blood glucose | Below 6.1 mmol/L | 6.1 to 6.9 mmol/L | 7.0 mmol/L or higher |
| Glucose 2 hours after a sugary drink | Below 7.8 mmol/L | 7.8 to 11.0 mmol/L | 11.1 mmol/L or higher |
Here is what these two tests involve:
- Fasting blood glucose. “Fasting” means you have nothing to eat or drink, apart from plain water, for at least 8 hours before the blood is taken.[7] Most people do this overnight.
- Glucose tolerance test. You give a fasting blood sample. You then drink a very sweet glucose drink, and your blood is tested again 2 hours later. This shows how well your body clears glucose from the blood.
There is also a third test, called HbA1c. It shows your average blood sugar over the past two to three months, and the result is given as a percentage.[8] MOH guidance for doctors says that 6.0% or below fits with no diabetes, and 7.0% or above fits with diabetes. A result from 6.1% to 6.9% means your doctor will ask for a fasting glucose test or a glucose tolerance test to find out more.[9]
Ranges differ a little between countries. The American Diabetes Association, for example, has recommended a lower fasting cut-off for pre-diabetes than the 6.1 mmol/L used in Singapore.[10] If you see different numbers online, that is often the reason. Your doctor will explain what your own results mean.
Under the Health Promotion Board’s Screen for Life programme, Singaporeans aged 40 and above are recommended to be screened every three years.[11] Our guide to the silent signs of diabetes explains who should be screened and what the visit involves.
Why Diabetes Matters
Many people with type 2 diabetes feel well, so the damage can build up quietly. High blood sugar over many years can lead to serious problems:[3]
- Heart attack and stroke. These happen when blood flow to the heart or the brain is blocked.
- Kidney failure. The kidneys filter waste out of your blood. Diabetes is one of the leading causes of kidney failure.
- Blindness. High blood sugar can damage the retina, the layer at the back of the eye that senses light. This damage is called retinopathy.
- Nerve damage. When this affects the feet, you may not feel small injuries. These can turn into foot ulcers, which are open sores that heal slowly. In serious cases, a foot or leg may need to be removed by surgery. This is called an amputation.
The good news is that these outcomes can often be avoided or delayed. Medicine, regular screening, and early treatment of complications all help. Screening includes kidney checks and eye exams to look for retinopathy.[3][12]
Diabetes can also cause emergencies. Two of the most important are diabetic ketoacidosis (DKA), a dangerous build-up of acids in the blood, and low blood sugar. We cover both in the articles linked below.
Can Diabetes Be Cured?
Diabetes is a long-term condition, and the answer depends on the type.
Type 1 diabetes needs insulin every day.[3]
Type 2 diabetes can go into remission for some people. Remission means blood sugar stays below the diabetes level without the need for diabetes medicine. NHS Scotland defines it as an HbA1c below 6.5% for at least three months without medication.[13] Remission is not the same as a cure, because blood sugar can rise again.[13] The strongest evidence suggests remission comes mainly from weight loss, and it is possible for some people early in the course of type 2 diabetes.[13][14]
Where to Go Next
Pick the article that matches what you need.
If you’re wondering whether you might have it:
- Silent signs of diabetes: symptoms, risk factors, and screening in Singapore.
If you want to lower your risk or manage it through food:
- Eating right for diabetes prevention
- White rice and diabetes risk
- The glycaemic index
- The blood sugar rollercoaster: what alcohol does
- Diabetes and Christmas in Singapore
If you’re managing diabetes and want to avoid emergencies:
- Ketones and diabetes: when to test and the SGLT2 inhibitor risk.
- Suspect DKA? What to do right now
Frequently Asked Questions
Is diabetes caused by eating too much sugar?
Not in a simple way. Type 1 diabetes is not caused by diet or lifestyle.[4] For type 2, the WHO lists several risk factors: excess weight, family history, physical inactivity, tobacco use, and too much alcohol.[15] Food is one part of that picture.
Can young people get type 2 diabetes?
Yes. You can get type 2 diabetes at any age, even during childhood.[2]
If I feel fine, can I still have diabetes?
Yes. People with type 2 diabetes can feel well and have no symptoms at all.[11] That is why screening matters.
The Bottom Line
Diabetes means too much glucose in your blood, because your body does not make or use insulin properly. Type 2 is by far the most common type, and it often causes no symptoms at first. A simple blood test can find it, and finding it early gives you the most options. Use the links above to go deeper on whatever matters to you right now.
Sources
- Ministry of Health: National Population Health Survey 2024
- Women’s Health (US Department of Health and Human Services): Diabetes
- World Health Organization: Diabetes fact sheet. The point that medicine, screening, and treatment of complications can avoid or delay problems also appears on the UN’s World Diabetes Day page, which draws on WHO guidance.
- HealthHub: Types of Diabetes, Diabetes Hub
- HealthHub: Understanding Prediabetes, Signs, Symptoms and Treatment (includes the comment from Dr Goh Su Yen, Singapore General Hospital, that almost everyone who develops type 2 diabetes passes through pre-diabetes first)
- Ministry of Health: Studying Measures to Better Support Persons with Pre-Diabetes (14 November 2017)
- Centre for Population Health Sciences / CFPS guidance on fasting (no calories for at least 8 hours). [Fiona: add the exact URL used in the earlier research before publishing.]
- Glycated Hemoglobin and Incident Type 2 Diabetes in Singaporean Chinese Adults: The Singapore Chinese Health Study, PMC
- Ministry of Health: Circular 08/2019, HbA1c as a screening test (hosted by Diabetes Singapore)
- Screening for diabetes with HbA1c among Chinese, Malay and Indian community residents in Singapore, PMC
- HealthHub: Diabetes Mellitus and Screen for Life
- United Nations: World Diabetes Day
- NHS Scotland Right Decisions: What Is Remission and Why Does It Matter?
- NHS Scotland Right Decisions: Achieving Remission
- WHO South-East Asia Region: Diabetes fact sheet