A person who has untreated diabetes is likely to complain of symptoms like feeling thirsty (polydipsia) all the time, drinking a lot of water and passing large amounts of urine(polyuria), weight loss (some patients describe a feeling of emptiness in the stomach and wanting to eat frequently(polyphagia)), and tiredness. The person may report that at times they have felt faint or dizzy and may even have "blacked out" (become unconscious). This can happen if the blood glucose levels fall too low to support normal brain function.

If you do a urine dipstick test and find evidence of sugar, this is a strong sign of diabetes because some of the excess glucose in the blood is filtered out by the kidneys and passes into the urine. If you detect sugar in a person's urine you should suspect diabetes and refer them to the nearest higher level health facility.

  • Can you suggest another sign of diabetes, which you might be able to detect on the breath of a diabetic person?
  • When the level of ketones rises in the blood of a person with diabetes, their breath has a distinctive "fruity" smell.

Another sign of uncontrolled diabetes that has gone on for a long time is numbness in the fingers and toes, or gradual loss of vision. This is because persistently high levels of glucose damage the delicate blood vessels (capillaries) serving the extremities and the eyes, so they become starved of oxygen and nutrients and can no longer function normally.

Classification of Diabetes

There are several types of diabetes, including two that are common: Type 1 and Type 2. Worldwide, about 90% of people with diabetes have Type 2 and about 10% have Type 1. Gestational diabetes accounts for very small numbers of cases during pregnancy. We will look at each type in turn.

Type 1 diabetes

Type 1 diabetes was previously called insulin-dependent diabetes. This is because in people with Type 1 diabetes their pancreas fails to produce enough insulin due to the destruction of the cells that make insulin. Without enough insulin, glucose cannot enter the tissues and cells, and so the blood glucose level rises damagingly high.

People with Type 1 diabetes are dependent on taking insulin every day - either in tablet form or injecting it. Although there is plenty of glucose in the blood, it cannot enter the tissues and, because of this, it cannot be used as a fuel source. Instead, the body breaks down fats and protein to use as fuel. As a result, the person often loses weight very rapidly due to loss of fluid, an inability to use glucose as a fuel, loss of muscle as protein is broken down, and loss of glucose in the urine.

A person with Type 1 diabetes should never stop taking their insulin, even when they are unwell and not eating. Type 1 diabetes can develop at any age, although it most commonly begins in children and young adults.

Type 2 diabetes

Type 2 diabetes was previously called non-insulin-dependent diabetes, because the pancreas still produces insulin, though the amount reduces over time. The main problem is that the body cells become increasingly resistant to the action of insulin, so it does not stimulate the cells sufficiently to take up glucose from the blood. Symptoms such as thirst and passing large amounts of urine may be absent.

Type 2 diabetes may be present for many years before a diagnosis is made, because some people have few symptoms or take no notice of them, e.g. they may not see their thirst or getting up at night to pass urine as a problem. Having Type 2 diabetes for several years before a diagnosis is made can mean that complications of diabetes, which take years to develop, may already be present at the time of diagnosis.

Overeating and lack of exercise are two particularly important factors thought to be contributing to the rapidly increasing numbers of people worldwide with Type 2 diabetes. Although it is most often a condition that develops in adults, particularly those aged over 40 years, it is beginning to be diagnosed in younger adults and even in teenagers who are obese.

The amount of insulin that is produced in someone with Type 2 diabetes often decreases over a period of years, and eventually insulin treatment is required. Treatment generally starts with changes in the amounts and types of food eaten and an increase in physical activity, before progressing to tablets and then onto insulin injections.

Gestational diabetes

A pregnant woman can develop diabetes in pregnancy, due to chemical changes in her body. This is known as gestational diabetes (also known as pregnancy-induced diabetes). The common symptoms are the same as for Type 1 and Type 2 diabetes (thirst, frequent urination), but she may also complain of itching and an unpleasant smell coming from her vagina due to infection, and wounds that are slow to heal. Gestational diabetes commonly goes away after the baby is delivered, but you should be aware that a few mothers will have undiagnosed Type 2 diabetes, or have developed coincidental Type 1 diabetes. Also, having had a diagnosis of gestational diabetes, a woman is more likely to develop diabetes in future pregnancies and is also more likely subsequently to develop Type 2 diabetes. During the pregnancy, the woman should be treated for diabetes by changes to her diet and exercise, with or without prescribed insulin.

Last modified: Tuesday, 28 February 2017, 7:02 PM