Did you know that 1 in 3 people in Singapore is at risk of diabetes? Whereas only 1 in 9 people aged 18 to 69 was affected by the disease in 2010, technological advancements had paved the way for increasingly sedentary lifestyles in the last decade. Without any intervention, it is projected that 1 million people in Singapore will have diabetes come 2050.

Singapore is not alone in this crisis. Worldwide, about 537 million adults aged 20 to 79 years old are affected – a number expected to hit 783 million by 2045. If you think diabetes is a concern reserved for old age, think again. Over 1.2 million Type 1 diabetes are 19 years old and below, and nearly half of diabetic adults remain undiagnosed – a testament to the lack of education on the disease.

Health impact wise, adults with diabetes are 2 to 3 times more likely to suffer a heart attack or stroke. Diabetes is also the leading cause of blindness and kidney failure. Studies have also shown that diabetics are more likely to have poorer outcomes for several infectious diseases including Covid-19.

Staying uninformed against a backdrop of rising numbers and low awareness comes with a price, which is why we put together this comprehensive guide to diabetes. 

What is diabetes?

Diabetes mellitus (DM) is a chronic disease which involves issues with metabolism of sugar in the blood. When consuming carbohydrates (including sugar and starch, etc.), these foods become dextrose after digestion, turning into glucose as they are absorbed into blood circulation system by the small intestine. The pancreas secretes insulin, helping cells absorb this glucose for use by the body as energy.

The glucose level in the blood rises when the pancreas does not secrete sufficient insulin, or the body cannot make use of the insulin produced (this is known as insulin resistance). This results in abnormal levels of sugar in the blood while the body is starved of energy.

Four Common Types of diabetes

1. Type 1 Diabetes (T1DM)

Type 1 diabetes is a form of diabetes characterised by the lack of insulin. Insulin is an important hormone produced by the organ pancreas to ‘shuttle’ sugars from the blood into the cells. Type 1 diabetes is an autoimmune system where the body attacks the pancreatic cells, resulting in the cells no longer being able to produce insulin.

Symptoms of Type 1 Diabetes

Common symptoms for Type 1 diabetes are sudden, unplanned weight loss, onset of nausea and/or vomiting, extreme fatigue and increased thirst and frequent urination.

Causes of Type 1 Diabetes

Genetic predisposition - family history of a parent or direct sibling being diagnosed with diabetes. Type 1 diabetes normally occur in children to young adults.

2. Type 2 Diabetes (T2DM)

Type 2 diabetes, or T2DM is the most commonly form of diabetes mellitus. Where Type 1 diabetes occurs due to a lack of insulin secretion in the body, Type 2 diabetes is caused by the inefficient use of insulin or ‘faulty signalling’ in the cells, also known as insulin resistance. This is a phenomenon where the body is less receptive to the presence of insulin, resulting in a rise in blood sugar levels because it cannot be directed into the cells.

Symptoms of Type 2 Diabetes

T2DM is also termed a ‘silent disease’ as its symptoms are less noticeable especially in the very beginning. Overtime, the symptoms that appear share some similarities with Type 1 diabetes, such as frequent urination and extreme thirst. Other symptoms include yeast infections, slow healing of cuts and wounds and numbness in the feet and fingers.

Causes of Type 2 Diabetes

Type 2 diabetes is largely a product of weight gain from a rich diet and a sedentary lifestyle. Other risk factors include age and family history of diabetes, though these play a smaller role.

3.  Gestational Diabetes (GDM)

Gestational or pregnancy diabetes is a phenomenon that occurs only in some women during pregnancy. This occurs when blood glucose levels are higher than normal but lower than the diagnosis of diabetes, translating to a higher risk of type 2 diabetes for the mother down the line and could spell complications during one’s term and delivery.

Symptoms of Gestational Diabetes

Gestational diabetes mellitus (GDM) is normally diagnosed through prenatal screening as there are no outward signs or symptoms.

4. Prediabetes

Prediabetes: as its name goes, it is the stage before actual diabetes. Prediabetes is coined as a condition where the blood sugar readings are higher than a normal person’s blood sugar levels, but not high enough to be medically diagnosed as diabetes. If untreated,  people with prediabetes normally end up with full blown diabetes (Type 2 diabetes).

Unlike Type 1 and 2 diabetes, prediabetes is reversible through a combination of physical activity and dietary changes. People with pre-diabetes should get their blood sugar level measured every six months to get a good gauge on how their food intake and current lifestyle affects their health.11

People over 40 who have normal blood sugar levels, but with a family history of Type 2 diabetes, should also undergo regular health screenings.

Difference between Type 1 and type 2 Diabetes

Below is a guide to some of the main differences between type 1 and type 2 diabetes. 

The main difference between Type 1 and type 2 diabetes is that type 1 diabetes is a genetic condition that often shows up early in life, and type 2 is mainly lifestyle-related and develops over time. With type 1 diabetes, your immune system is attacking and destroying the insulin-producing cells in your pancreas.11 

  Type 1 Diabetes Type 2 Diabetes
What is happening? Your body attacks the cells in your pancreas which means it cannot make any insulin. Your body is unable to use the insulin produced properly.
Risk factors Genetics

Family history – any parent or direct sibling being diagnosed with Type 1 DM
Family history
Lifestyle factors such as overweight, lack of physical activity, smoking, alcohol

Unplanned loss of weight

Nausea / Vomiting


Increased thirst / urination


Increased thirst / urination

Yeast infections

Slow healing wounds/cuts

Management Type 1 is managed mainly by taking insulin to control your blood sugar.

Early stages of Type 2 DM may be managed with dietary intervention + exercise

Next stage will be oral anti-diabetic medications with diet control and exercise

Late stage will be the use of insulin to manage the disease

Cure and prevention Currently there is no cure for type 1 but research continues.

Type 2 cannot be cured but it can be well managed through medication and lifestyle changes

Leading a healthy lifestyle is key to lower risks of Type 2 DM

Risk Factors for Diabetes

Risk factors for diabetes can be divided into non-controllable risk factors and controllable risk factors. Non-controllable factors are factors that cannot be changes such as your age or family history.

Controllable factors are normally lifestyle factors such as diet and exercise, which can be altered to lower one’s risks.

Non-Controllable Risk Factors:

  • Age – risk of developing diabetes increases with age especially after 40 years old
  • Genetic disposition – family history of diabetes occuring in direct family members i.e. parents or siblings

Controllable Risk Factors

  • Overweight – having a Body Mass Index (BMI) of 23.0kg/m2 or more
  • Leading a sedentary (inactive) lifestyle
  • Smoking

Diabetes can also be predisposed by some endocrine diseases, pancreatic diseases and drugs e.g. steroids.

Early Signs of Diabetes

Both Type 1 and Type 2 diabetes share similar warning signs as follows:

Hunger and fatigue
One of the early signs for diabetes is increased hunger and fatigue, caused by insufficient insulin produced by the body. In a healthy body, food is converted into glucose that cells use for energy. If insufficient insulin is produced, they will not be able to absorb the glucose, hence resulting in these symptoms.

Frequent urination (polyuria) and extreme thirst (polydipsia)
While the average person goes to the bathroom for up to seven times in 24 hours, persons with diabetes may have to go more often. This is because the body reabsorbs glucose as it passes through your kidneys. However, as diabetes pushes the blood sugar up, the kidneys may not be able to bring it all back in - resulting in the body making more urine and having the need to consume more water, due to thirst.

Dry mouth and itchy skin
With more urine output, the body will use more fluids in order to produce the urine. As a result, there is less water for other body parts which may cause a feeling of dryness in the mouth and dehydration. The skin may also become dry and start to itch.

Blurred vision
As fluid levels in the body change, it could result in the lenses in your eyes swelling up. Due to the change of shape of the lenses, you may notice that your vision is sometimes out of focus.

Common Symptoms of Type 2 Diabetes

If your blood glucose level has been high for a prolonged period of time, these are the symptoms that may appear.

Yeast infections
Yeast thrives off glucose. A high blood glucose level is conducive for yeast to thrive, resulting in yeast infections. These infections can grow in any warm, moist fold of skin, including:

  • Between fingers and toes
  • Under the breasts
  • In or around sex organs

Slow-healing sores or wounds
Prolonged periods of high blood sugar can also affect your blood flow. This causes nerve damage that makes it hard for your body to regenerate and heal from cuts and other wounds.

Pain or numbness in the feet or legs. 
Pain and numbness in your lower limbs may also be another sign of nerve damage.

Diagnosing Diabetes

Testing your normal and fasting blood glucose levels remains the most straightforward indicator of risk, and below is a nifty guide from World Health Organisation (WHO) to interpreting your blood test results.

Fasting glucose
< 5.6 mmol/L ≥5.6 to < 7 mmol/L ≥7 mmol/L
2 Hours after Meal < 7.8 mmol/L Normal Impaired Fasting Glucose Diabetes
≥7.8 to < 11.1 mmol/L Impaired Glucose Tolerance Impaired Glucose Tolerance Diabetes
≥11.1mmol/L Diabetes Diabetes Diabetes

Meanwhile, the other tests follow Clinical Practice Guidelines laid out by Singapore’s health ministry. According to them, a patient has diabetes if their readings cross the following thresholds

Casual Glucose test ≥ 11.1 mmol/L
Glycated hemoglobin (HbA1C) test  ≥ 7.9 mmol/L
Oral Glucose Tolerance Test (OGTT) ≥ 11.1 mmol/L

Diabetes Management

You may wonder: What does living with the disease look like? Since the causes of type 1 and 2 diabetes differ, so do their management. People with type 1 diabetes, where the pancreas can no longer product insulin, will have to administer the hormone externally for energy and blood glucose control. Doctors will pick from 5 types of insulin – rapid-acting, short-acting, intermediate-acting, long-acting, and premix – and recommend their dose and frequency.

While type 2 diabetes may also require insulin at a later stage, treatment usually starts out with dietary and lifestyle intervention (improving their eating habits and embarking on an exercise program).

If changes in diet is inadequate in managing blood sugar levels, then oral medication will be prescribed to manage blood sugar levels.

Diabetic Diet

Diabetic patients should follow the treatment solutions prescribed by their doctor to actively manage the disease and reduce the risk of complications.

All patients should follow dietary treatment. As different people have varying calorie requirements, patients should consult a registered dietician to design a suitable menu for the management of the disease and stabilizing glucose. The general guidelines are as follows:

Have a balanced diet and have your meals at a regular time. Also dieticians and doctors may also advise patients “eat less per meal, but have more meals”. This helps in stabilizing blood glucose levels.

Your diet should have a healthy and appropriate mix of carbohydrates. Carbohydrates should be approximately 50% of the total calorie intake. For example, around 750 kcal of calories (equivalent to around 188g carbohydrate, i.e., of 18 - 19 portions of carbohydrate exchange) to be produced by carbohydrate in a 1500 kcal menu.

The above carbohydrate exchange should be distributed evenly in main meals and snack time. 1 portion of carbohydrate exchange is equivalent to 10g of carbohydrate.

Patients can choose suitable number of grains, rhizome vegetables, fruits and dairy according to the “carbohydrate exchange” method.

Dietary counselling would include emphasis on the avoidance of food and drinks that are rich in sugar or additional sweeteners to prevent surge of glucose as much as possible.

Foods that are high in saturated fat content such as animal organs should also be avoided to protect the cardiovascular system.

Abstinence of alcohol should also be follow as alcohol consumption can affect the efficacy of drugs and may lead to low blood glucose (hypoglycaemia) . In unavoidable circumstances, men and women should limit themselves to 2 and 1 portions respectively. Each portion works out to be 300ml of beer, 150ml of red wine, or 45ml of spirit, depending on one’s choice of a nightcap.

Oral Anti-Diabetic Drugs (OAD)​

The prescriptions of oral anti-diabetic drugs will be given by doctor according to the body condition, drug allergies (if any) and condition of blood glucose control of individual patient.

Type  Function  Example
Sulfonylureas Stimulate the insulin secretion of pancreas  Tolbutamide
Gliclazide MR
Biguanides Reduce the production of glucose in liver, increase the application of glucose by body tissue (muscles) and reduce the absorption of glucose in gastrointestinal tract Metformin
Metformin XR
α-Glucosidase Inhibitors  Slow down the absorption of dextrose in small intestine so as to prevent too much glucose after meals Acarbose
Glitazones Increase the sensitivity of body to insulin so glucose would enter into the cells and decrease the glucose level. Pioglitazone
Dipeptidyl Peptidase-4 Enzyme Inhibitors  Stimulate the insulin secretion of pancreas   Sitagliptin
Meglitinides / Glinides Stimulate the insulin secretion of pancreas Repaglinide
SGLT2-inhibitors Inhibit reabsorption of glucose in the kidney and lower blood sugar, e.g., empagliflozin, dapagliflozin Dapagliflozin Empagliflozin

Insulin Injections for diabetes

Insulin is a hormone required by the body to use glucose for energy and helps balance your blood glucose levels.

For Type 1 DM and late-stage Type 2 DM where the pancreas can longer produce insulin, diabetics would have to administer insulin externally to help regulate blood sugar levels.

Injection of insulin is a way similar to the normal secretion of insulin to manage glucose. This treatment is applied to type 1 patients and some of the type 2 patients whose glucose level cannot be managed after application of oral hypoglycemic medications.

Injection of insulin can be classified into 5 durations of action of insulin, it would be rapid acting, short acting, intermediate acting, long acting and pre-mix insulin. The doctors will generally decide the type, dose of insulin and the frequency of injection required and the injection can be done by the patients themselves after training.

Diabetes Complications

If not well managed, the continued presence of high sugar levels in the bloodstream can lead to complications over time. The complications differ from those suffering from Type 1 and Type 2 diabetes.

Acute Complications of Type 1 Diabetes

Type 1 diabetes sufferers tend to experience the consequences of high glucose levels quickly as compared to Type 2 diabetics.

Leaving high blood sugar levels to chance jeopardises the metabolism of fat and protein, which doesn’t bode well, especially for type 1 diabetics. Where insulin is scarce, the body breaks fat down into fuel. This creates a build up of ketone bodies which can potentially cause ketoacidosis and life-threatening cases of diabetic coma. Patients could also experience glycosuria, where sugars are passed out during urination; as well as excessive urination (polyuria) and extreme thirst (polydipsia) arising from dehydration and electrolyte imbalance. 

Chronic Complications for Type 2 Diabetes

The complications of type 2 diabetes, on the other hand, put systems and organs at risk of destruction. As high blood sugar levels persist, patients are more vulnerable to cardiovascular diseases, kidney failure, or damage to one’s tissues and nerves. The latter can result in retinopathy leading to visual impairment and foot diseases such as ulcers, infections, and gangrene – which may warrant lower limb amputation.

Unsurprisingly, foot care is a big part of living with type 2 diabetes. Maintaining foot hygiene is the bare minimum, along with regular examination lest cuts and wounds on numb limbs go undetected. For the same reason, patients should never go barefoot, trim their toenails with care, and have calluses removed professionally. Exercise should be limited to feet-friendly activities, and investing in footwear that fits well and promotes blood circulation will prove worthwhile.

Diabetes Prevention

As the saying goes, an ounce of prevention is worth a pound of care. Living with diabetes is a huge undertaking, and it’s wiser to be more proactive than reactive. Regular exercise and dietary management are two cornerstones of diabetes prevention , but what do these look like in practice?

For adults, the World Health Organisation (WHO) recommends 75 and 150 minutes of exercise of moderate and vigorous intensities respectively per week. That said, those who are gunning for a healthy BMI could use more activity. During mealtimes, favour complex over processed carbohydrates; poultry, fish, and plant-based protein over red meat; and water, coffee, and tea over sugary drinks. Home-cooked meals are also a good idea if you’re using healthier fats and oils made with olives, avocados, and nuts.

Working out and eating well aside, diabetes risk assessments and health check-ups cannot be understated either. In Singapore, people aged between 18 and 29 can use the former, while those above 40 years old are advised to undergo the Health Promotion Board's (HPB) Screen for Life program once every three years.  Here are some other lifestyle adjustments that will keep you out of the woods.

Understanding diabetes

The bad news is that there’s no proven cure for diabetes. The good news? Prediabetes can be mitigated. As you would have learned by now, blood sugar levels sit front and centre in diabetes management, treatment, and prevention. Now that you know the risks, causes, and manifestations of diabetes, you can be more intentional about your diet, exercise regime, and health screenings.