Diabetes overview: controlling an insulin condition

Muiris Houstons looks at causes, signs, symptoms, prevention, treatment and useful resources.


Diabetes Mellitus occurs when there is excessive sugar in the blood. The term ‘diabetes’ means excessive urination and the word ‘mellitus’ means honey.

There are two distinct types of diabetes. Both are caused by a lack of sufficient insulin, which is produced by the pancreas gland.

Type I diabetes is also known as insulin-dependent diabetes and happens when the body produces insufficient insulin. It mainly occurs in young people and children and it requires the depleted insulin to be replaced through regular injections.

Diabetes type 2 or non-insulin-dependent diabetes mainly affects older people and those who are overweight. It occurs when more sugar is consumed than the insulin produced by the body can handle. It is treated with diet and oral medication although some people with this version of diabetes will eventually require insulin injections.

Untreated diabetes affects many body systems and is linked to the development of other conditions such as heart disease, kidney disease and eye disease.


While diabetes cannot be cured, the condition can be controlled. A combination of sensible weight loss, avoidance of sugar and refined carbohydrates and increased exercise may be sufficient to control Type 2 diabetes. If you have type 1 disease, then carefully matching your blood sugar levels to the dose of injected insulin can produce good, tight control.

The International Diabetes Federation estimate there are over 91,000 people with diabetes in Ireland, with a prevalence of 6.1 per cent of the population.

According to Diabetes Ireland there are about 30,000 people here with the disease but who remain undiagnosed.


Type 1 diabetes is caused by the body’s own immune system destroying the insulin making cells in the pancreas. It tends to occur in childhood. Type 2 diabetes develops slowly in adults and is linked to lifestyle, especially being overweight and not exercising sufficiently.

The symptoms of diabetes include an excessive and frequent need to pass urine, excessive thirst, tiredness and lack of energy. Some people notice an increased tendency to develop infections especially those of the skin. Weight loss is common in Type I diabetes.

When your doctor examines you there may be no outward signs of diabetes, especially with type 2 disease. However if you have developed some complications they may find you have high blood pressure or there may be evidence of the disease when they examine your neurological system or look at the back of your eye. Spot testing your urine for sugar may also indicate the possibility of diabetes.

Ultimately the diagnosis is made by blood test. A fasting blood glucose above a certain level strongly suggests the diagnosis. In borderline cases you may be asked to undergo a glucose tolerance test where you drink the equivalent of a bottle of Lucozade after which your blood sugars are checked. A test called the Haemoglobin 1Ac, initially developed as a means of monitoring diabetes control is now also used as a diagnostic test.


Of the many chronic diseases that can affect the body, diabetes tops the list when it comes to the wide range of complications that can result, especially if you don’t look after yourself. Many of the complications are the direct result of damage to blood vessels throughout the body.

Coronary heart disease occurs more frequently in people with diabetes. It particularly affects the distal part of the arteries that provide blood supply to the heart.

Retinopathy is a diabetes complication affecting the eye. It can threaten your sight if not diagnosed early. There are two reasons why diabetic retinopathy can happen. The first is when the small blood vessels surrounding the retina leak, leading to the loss of central vision but retention of peripheral vision. On a practical level this means that it becomes difficult to distinguish faces, reading is problematic and negotiating inside and outside the home can be difficult.

Secondly, the condition can also occur when abnormal new vessels develop and bleed into the eye, which can severely reduce sight or result in complete loss of vision in the affected eye. But treatment with modern lasers is effective at limiting the damage done to the inner lining of the eye (the retina).

Nephropathy is the medical name for kidney disease. Diabetes can damage the kidneys so that they work less efficiently. Ultimately it is possible to develop kidney failure as a result.

Neuropathy refers to the nerve damage that diabetes may cause. Like many other diabetes complications it is the direct result of having poorly controlled blood sugar over a period of time. As a result of nerve damage to the peripheral nerves, sensation is reduced. This can result in repeated injury to your hands and feet because you can no longer sense changes in pressure or temperature. In addition, damage involving nerves in the arms, hands, legs and feet, can result in a distortion to sensation, producing tingling or burning pain.

The part of the nervous system that controls balance may be affected as well as the ability to know exactly where your feet are in relation to the ground, putting you at risk of falls.


Type 2 diabetes can be prevented by watching your weight and exercising regularly. It is no coincidence that as obesity levels in the Irish population have risen so too has the prevalence of diabetes. So a balanced diet and regular exercise is truly preventive for type 2 diabetes.

Unfortunately, type 1 diabetes cannot be prevented. A combination of genetic susceptibility and recent infection is thought to be the trigger for this form of the disease.

Self - administered insulin injections, usually given once or twice a day with a combination of long-acting and short-acting insulins is the first line treatment for type 1 diabetes. Insulin pumps, which deliver a steady stream of insulin are also used. And pancreas transplants, while not common, have been successfully used to treat some patients.

For type 2 diabetes, diet, weight loss and exercise may control the milder cases. However, oral drugs aimed at lowering blood sugar are commonly prescribed. These act either by increasing the secretion of insulin from the pancreas or by making the organs in the body such as the liver more sensitive to the limited amount of insulin produced by the body.

A particular side -effect of diabetes treatment is the risk of developing hypoglycaemia. This can happen when blood glucose levels go below a certain level, causing a range of symptoms. You may feel shaky, dizzy or have heart palpitations. You may also feel anxious or excited, sick or hungry, complain of having a headache or blurred vision. Hypoglycaemic episodes can happen for a variety of reasons including taking too much insulin or oral diabetic tablets, missing or delaying a meal or because of strenuous exercise.

It can also happen during another illness such as vomiting or diarrhoea or infection. Alcohol consumption can also trigger it, as can hot weather.

If a “hypo” is not treated promptly the person with diabetes can lose consciousness. As soon as you become aware that you are feeling unwell you should take something high in glucose such as glucose sweets or a sugary drink (not a diet drink).

Sometimes you can miss the early signs of a hypo and become agitated and confused. If this happens a friend or relative should strongly encourage you to have a sugary drink. However if you become unconscious then trying to make you eat or drink could cause you to choke. In case this happens let your family and friends know that you carry an injectable medication called glucagon and teach them how to use it. Administered directly into a person’s thigh, it quickly raises the level of glucose in the blood.


Diabetes Ireland, 19 Northwood House, Santry Dublin 9 (01 8428118) or (1850 909 909)

www.diabetes.ie Ireland’s diabetes advocacy group and a useful one-stop shop for information and guidance.

www.diabetes.org.uk. Diabetes UK has a Northern Ireland section on its website


Dr Muiris Houston is a specialist in general practice and occupational medicine and a medical education consultant