Diabetes, also known as diabetes mellitus, is a chronic metabolic condition in which the body is unable to regulate blood glucose (sugar) levels effectively, resulting in blood glucose that runs persistently higher than normal. It is one of the most significant public health concerns in Singapore, where more than 450,000 people are currently living with diabetes and one in three residents has a lifetime risk of developing the condition.
Diabetes cannot currently be cured, but it is highly manageable. With the right combination of lifestyle changes, monitoring, and medication, most people with diabetes can maintain blood glucose within a healthy range, feel well day to day, and substantially reduce their risk of long-term complications. The greatest risk comes not from the diagnosis itself, but from diabetes that goes undetected or poorly controlled over many years — nationally, close to one in five people with diabetes remain undiagnosed, and around three in five of those with a known diagnosis do not meet recommended blood glucose targets.
Blood glucose regulation depends on insulin, a hormone produced by beta cells in the pancreas. After eating, carbohydrates are broken down into glucose, which enters the bloodstream. Insulin acts as a key that allows glucose to move out of the blood and into cells throughout the body, where it is used for energy or stored for later use.
Diabetes is often called a “silent” disease because blood glucose can run high for years without causing symptoms severe enough to prompt a doctor's visit — which is why regular screening, not just symptom-watching, is central to catching it early.
Type 1 Diabetes
An autoimmune condition in which the immune system destroys the insulin-producing cells of the pancreas, usually beginning in childhood or young adulthood, though it can develop at any age. The body produces little to no insulin, so lifelong insulin therapy (by injection or pump) is required from diagnosis onward. Accounts for a minority of diabetes cases overall.
Type 2 Diabetes
The most common form of diabetes, typically developing in adulthood and strongly linked to excess weight, physical inactivity, and genetics, though it is increasingly seen at younger ages. Involves a combination of insulin resistance and, over time, declining insulin production. A progressive condition — treatment often needs to be intensified over the years, though good early control can significantly slow this progression.
Gestational Diabetes
Diabetes that develops during pregnancy due to hormonal changes that increase insulin resistance. Usually resolves after childbirth, but requires careful blood glucose control during pregnancy to protect both mother and baby, and it meaningfully raises the mother's future risk of developing Type 2 diabetes.
Prediabetes
Blood glucose levels that are higher than normal but not yet high enough to meet the diagnostic threshold for Type 2 diabetes. An important window of opportunity — prediabetes is often reversible with structured lifestyle changes such as weight loss and regular exercise, which can prevent or significantly delay progression to Type 2 diabetes.
Secondary diabetes
Diabetes arising from a specific identifiable cause, such as physical damage to the pancreas (from pancreatitis or surgery), certain medications (including long-term corticosteroid use), or other endocrine conditions. Less common, but important to identify as it can change the treatment approach.
Type 1 diabetes often presents suddenly, over days to weeks, particularly in children and young adults. Type 2 diabetes tends to develop gradually, and many people have no noticeable symptoms at all in the early stages — which is why it is frequently picked up on routine screening rather than through symptoms.
Diabetes and prediabetes are diagnosed using blood tests that measure glucose levels, either directly or as a reflection of average control over recent months. More than one abnormal result, or a second confirmatory test, is generally required before a diagnosis is made.
HbA1c: The HbA1c test is a simple blood test that measures your average blood sugar levels over the past two to three months. It looks at how much sugar is stuck to your red blood cells. No fasting is required before the test. Doctors use it to find out if you have prediabetes or type 2 diabetes.
Fasting Blood Glucose: A Fasting Blood Glucose test measures your blood sugar level after you do not eat or drink anything except water for at least 8 hours. It is a basic tool used to check for prediabetes and diabetes by showing how well your body handles sugar when fasting.
Oral Glucose Tolerance Test: It measures how your body handles a large dose of sugar. It involves fasting overnight, taking a baseline blood sample, drinking a liquid with 75 grams of glucose, and testing your blood again after two hours to check for diabetes or prediabetes.
Random Blood Glucose: A random blood glucose test measures your blood sugar at any time of day, regardless of when you last ate. A result of 200 mg/dL (11.1 mmol/L) or higher, especially when paired with classic diabetes symptoms like extreme thirst or frequent urination, strongly suggests diabetes.
Persistently elevated blood glucose gradually damages blood vessels and nerves throughout the body. This is why diabetes is described as a systemic condition rather than one that affects blood sugar alone — and why good long-term control matters even when a person feels entirely well.
The combination of reduced sensation (from neuropathy) and reduced blood flow (from vascular disease) means minor foot injuries can go unnoticed and heal poorly, sometimes progressing to ulcers or infection. The large majority of lower limb amputations in Singapore occur in people with diabetes, which is why routine foot checks and prompt attention to any wound are an essential part of diabetes care, not an optional extra.
