Type 1 diabetes is a lifelong condition in which the body can't control the amount of glucose in the blood. This is because the body can't produce the natural hormone insulin. If left untreated, symptoms include excessive thirst, passing excessive urine and weight loss.
Type 1 diabetes is also known as insulin-dependent diabetes mellitus.
Glucose is a simple form of sugar found in foods and sugary drinks - it's absorbed as a natural part of digestion. One function of your blood is to carry glucose around your body. When glucose reaches body tissues, such as muscle cells, it's absorbed and converted into energy. Insulin helps with the absorption process so it’s critical for regulating the glucose concentration. If you have a shortage of insulin, glucose can build up in your blood.
Insulin is secreted into the blood by your pancreas - a gland found behind your stomach. Type 1 diabetes develops when the cells in your pancreas that make insulin - called beta cells - are destroyed by your body's own immune system. Because of this, type 1 diabetes is known as an autoimmune disease.
There are two main types of diabetes: type 1 and type 2. Almost 900,000 Australians have diabetes. Type 1 diabetes is the rarer form, affecting about 10 percent of Australians with diabetes.
The initial symptoms include:
The symptoms can develop quickly - usually over a few weeks. In particular, marked weight loss, often over a short period of two to eight weeks is the main distinguishing symptom between type 1 and type 2 diabetes. The other symptoms listed above can occur in either type.
If type 1 diabetes isn't diagnosed or controlled properly, you can develop high blood glucose levels (hyperglycaemia). Sometimes the treatment itself can cause low blood glucose levels (hypoglycaemia). Both of these conditions can lead to complications.
Low blood glucose can occur if you exert yourself or don't eat enough foods that contain glucose while taking insulin. It can also happen if you take too much insulin, which leads to your cells taking up more glucose and therefore blood glucose levels falling. If you have low blood glucose, generally defined as under 3.5–4.0 mmol/L, you may feel faint, sweat and feel your heart pounding. If you don't treat this by eating or drinking something sugary, it can lead to confusion, collapse and even coma. This is often called a 'hypo'.
Most patients will develop high blood glucose levels from time to time. These will settle either of their own accord or in response to a change in the dose of insulin you're taking. Rarely, glucose can build up in your blood and reach dangerous levels if you don't have enough insulin in your bloodstream. This condition is called diabetic ketoacidosis and causes additional symptoms, including:
Diabetic ketoacidosis needs immediate medical treatment in hospital. Without this, the condition can lead to coma and even death.
Long-term, poorly controlled high blood glucose can be very damaging to your health and can increase your risk of heart disease, stroke, kidney failure, nerve damage and blindness. The risk of blindness has been greatly reduced in the last 20 years because of advances in specialist eye treatment and better insulin products. There is also better understanding now of how the body's functions are affected by diabetes.
The exact cause of type 1 diabetes isn't known. However, it's possible that it may be triggered by a virus or other autoimmune diseases, or it may run in your family.
If you think you may be developing diabetes, visit your GP. It's important to seek help early so you can get the treatment you need.
Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history. They may also ask for a urine sample to be tested for glucose and ketones. Urine doesn't usually contain glucose, but it can be detected if you have diabetes. However, diabetes is usually diagnosed with a blood test to measure the level of glucose in your blood. This might be a fasting glucose test, which is taken after you haven't eaten for at least eight hours, or a random glucose test done at any time.
If your GP can't make a definite diagnosis after these tests, you may have a glucose tolerance test. This measures how your blood glucose level changes over time after you swallow a sugary drink. You will need to fast overnight before having this test.
There isn't a cure for type 1 diabetes but it can be controlled.
Type 1 diabetes can be controlled with insulin. This allows glucose to be absorbed into cells and converted into energy, stopping it building up in the blood.
There are different kinds of insulin that work at different rates and act for different lengths of time. Each can have varying rates of success in different people - ask your doctor or diabetes educator for advice on which type is best for you.
There are two main methods of taking insulin:
Your doctor will advise you on the most appropriate method for you.
Controlling your blood glucose
If you have diabetes, it's very important to carefully control your blood glucose level in order to stay as healthy as possible. However, you may have a 'hypo', or near hypo, from time to time, so it's a good idea to keep some sugary food or glucose tablets with you to control it. You can also buy glucose gels that rapidly increase your blood glucose level.
A hypo is an emergency – so it's vital that friends and relatives know what to do should you have a hypo. They should ring 000 if concerned or if you can’t swallow or be woken.
You can monitor your blood glucose levels with a home test kit. It involves taking a pinprick of blood from the side of your finger and putting a drop on a testing strip. A meter will read the result automatically.
You can adjust both your diet and insulin to keep your blood glucose level within the normal range. Your 'normal' range will be specific to you but a general guide for adults is:
Your GP or diabetes educator can guide you on how to monitor and manage your blood glucose and will give you continuing support.
A healthy lifestyle
In addition to controlling blood glucose, your lifestyle is key to ensuring that diabetes has as little impact as possible on your health.
You can control your blood pressure by following the tips above, but you may also need to take medication. Similarly, the best way to control the level of cholesterol in your blood is to reduce the amount of fat in your diet.
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Last published: 30 July 2011
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