Diabetes is a medical condition in which the blood glucose levels remain persistently higher than normal. It is becoming more common in Singapore. This may be due in part to ageing population, unhealthy diets and lack of exercise.

Insulin is a hormone produced by the pancreas that allows your body cells to use blood glucose (sugar) for energy. Food is converted into glucose before it is absorbed into our bloodstream. The pancreas then releases insulin to move the glucose from the bloodstream into the body cells for use or storage. People with diabetes are unable to fully use the glucose in their bloodstream due to:

- lack of insulin in the body

- insulin is ineffective

There are several symptoms that you may experience if you have diabetes mellitus. You may feel very thirsty and pass lots of urine. You may also find that you are losing weight and that you feel tired all the time. Sometimes, patients complain of blurred vision. Others notice itching around the genitals, suffer from frequent skin infections or notice that that wounds take a long time to heal.

If you have any of these symptoms, particularly if you are overweight, have high blood pressure or close family members with diabetes mellitus, you should see your doctor to ask him/her to test you for diabetes mellitus.

Diabetes is diagnosed via a blood test and not a urine test. If you have the above symptoms, it may be possible to make the diagnosis on 1 blood test. However, if the blood sugar is not very high, you may require 2 separate blood tests on different days. Sometimes an oral glucose tolerance test is required. For this test, you will be required to see your doctor in the morning after fasting for at least 8 hours. This means that you should not eat or drink anything except water the night before the test. You should have been eating a normal diet for 3 days prior to the blood test and not exercise heavily the day before the test. Your doctor will give you a very sweet drink containing glucose and will take blood from you after 1 and 2 hours to decide if you have diabetes mellitus.

Type 1 diabetes mellitus has also been known as juvenile-onset diabetes mellitus or insulin dependant diabetes mellitus. This is the less common type and usually occurs in young persons below the age of 35. In this condition, the body is unable to produce insulin. Insulin is a hormone produced by the pancreas, a gland that is in the abdomen. Insulin is a hormone that controls the use of different fuels for energy. It is especially important because it allows the body to use glucose (simple sugar) instead of fats. When there is no insulin, the body cannot use or store the glucose that comes from food and this causes the blood sugars to become very high. Instead, the body uses fat as a source of fuel giving rise to some of the acute complications of diabetes mellitus.

Type 2 (adult-onset or non-insulin requiring) diabetes mellitus is much more common and is the type of diabetes that affects most Singaporeans. In this type of diabetes, there is no shortage of insulin (at least at the start of the disease). Instead, the cells and tissues of the body are unable to respond to the insulin produced by the pancreas. They have "insulin resistance.".

This type of diabetes commonly occurs in persons who are overweight and have high blood pressure. There are often other family members who also have the disease.