With type 2 diabetes, the illness and symptoms tend to develop gradually (over weeks or months). This is because in type 2 diabetes you still make insulin (unlike in type 1 diabetes).
However, you develop diabetes because:
• You do not make enough insulin for your body's needs; or
• The cells in your body do not use insulin properly. This is called insulin resistance. The cells in your body become resistant to normal levels of insulin. This means that you need more insulin than you normally make to keep the blood sugar (glucose) level down; or
• A combination of the above two reasons.
Type 2 diabetes is much more common than type 1 diabetes.
Who develops type 2 diabetes?
Type 2 diabetes used to be known as maturity-onset, or non-insulin-dependent diabetes. It develops mainly in people older than the age of 40 (but can also occur in younger people). In the UK about 1 in 20 people aged over 65 and around 1 in 5 people aged over 85 have diabetes. Type 2 diabetes is now becoming more common in children and in young people.
The number of people with type 2 diabetes is increasing in the UK, as it is more common in people who are overweight or obese. It also tends to run in families. It is around five times more common in South Asian and African-Caribbean people (often developing before the age of 40 in this group). It is estimated that there are around 750,000 people in the UK with type 2 diabetes who have not yet been diagnosed with the condition.
Other risk factors for type 2 diabetes include:
• Having a first-degree relative with type 2 diabetes. (A first-degree relative is a parent, brother, sister, or child.)
• Being overweight or obese.
• Having a waist measuring more than 31.5 inches (80 cm) if you are a woman or more than 37 inches (94 cm) if you are a man.
• Having pre-diabetes (impaired glucose tolerance). Impaired glucose tolerance means that your blood sugar (glucose) levels are higher than normal but not high enough to have diabetes.
People with impaired glucose tolerance have a high risk of developing diabetes and so impaired glucose tolerance is often called pre-diabetes.
• Having diabetes or pre-diabetes when you were pregnant.
What are the symptoms of type 2 diabetes?
As already mentioned, the symptoms of type 2 diabetes often come on gradually and can be quite vague at first. Many people have diabetes for a long period of time before their diagnosis is made.
The four common symptoms are:
• Being thirsty a lot of the time.
• Passing large amounts of urine.
• Weight loss.
The reason why you make a lot of urine and become thirsty is because blood sugar (glucose) leaks into your urine, which pulls out extra water through the kidneys.
As the symptoms may develop gradually, you can become used to being thirsty and tired and you may not recognise that you are ill for some time. Some people also develop blurred vision and frequent infections, such as recurring thrush. However, some people with type 2 diabetes do not have any symptoms if the glucose level is not too high. But, even if you do not have symptoms, you should still have treatment to reduce the risk of developing complications.
How is diabetes diagnosed?
A simple dipstick test may detect sugar (glucose) in a sample of urine. However, this is not sufficient to make a definite diagnosis of diabetes. Therefore, a blood test is needed to make the diagnosis. The blood test detects the level of glucose in your blood. If the glucose level is high then it will confirm that you have diabetes. Some people have to have two samples of blood taken and may be asked to fast. (Fasting means having nothing to eat or drink, other than water, from midnight before the blood test is performed).
It is now recommended that the blood test for HbA1c can also be used as a test to diagnose diabetes. An HbA1c value of 48 mmol/mol (6.5%) or above is recommended as the blood level for diagnosing diabetes.
In many cases diabetes is diagnosed during a routine medical or when tests are done for an unrelated medical condition.
What are the possible complications of diabetes?
Short-term complication - a very high blood sugar (glucose) level
This is not common with type 2 diabetes. It is more common in untreated type 1 diabetes when a very high level of glucose can develop quickly. However, a very high glucose level develops in some people with untreated type 2 diabetes. A very high blood level of glucose can cause lack of fluid in the body (dehydration), drowsiness and serious illness which can be life-threatening.
If your blood glucose level is higher than normal over a long period of time, it can gradually damage your blood vessels. This can occur even if the glucose level is not very high above the normal level. This may lead to some of the following complications (often years after you first develop diabetes):
• Furring or hardening of the arteries (atheroma). This can cause problems such as angina, heart attacks, stroke and poor circulation.
• Kidney damage which sometimes develops into chronic kidney disease.
• Eye problems which can affect vision (due to damage to the small arteries of the retina at the back of the eye).
• Nerve damage.
• Foot problems (due to poor circulation and nerve damage).
• Impotence (again due to poor circulation and nerve damage).
• Other rare problems.
The type and severity of long-term complications vary from case to case. You may not develop any at all. In general, the nearer your blood glucose level is to normal, the less your risk of developing complications. Your risk of developing complications is also reduced if you deal with any other risk factors that you may have, such as high blood pressure.
Complications of treatment
Hypoglycaemia (which is often called a 'hypo') occurs when the level of glucose becomes too low, usually under 4 mmol/L. Only people with diabetes who take insulin and/or certain diabetes tablets are at risk of having a hypo. Not all tablet medicines used for diabetes can cause a hypo.
A hypo may occur if you have too much diabetes medication, have delayed or missed a meal or snack, or have taken part in unplanned exercise or physical activity.
Symptoms of hypoglycaemia include:
• Blurred vision
• Tingling lips
• Mood change
To treat hypoglycaemia you should take a sugary drink or some sweets. Then eat a starchy snack such as a sandwich.
Note: hypoglycaemia cannot occur if you are treated with diet alone.
What are the aims of treatment?
Although diabetes cannot be cured, it can be treated successfully. If a high blood sugar (glucose) level is brought down to a normal or near-normal level, your symptoms will ease and you are likely to feel well again. You still have some risk of complications in the long term if your blood glucose level remains even mildly high - even if you have no symptoms in the short term. However, studies have shown that people who have better glucose control have fewer complications (such as heart disease or eye problems) compared with those people who have poorer control of their glucose level.
Therefore, the main aims of treatment are:
• To keep your blood glucose level as near normal as possible.
• To reduce any other risk factors that may increase your risk of developing complications. In particular, to lower your blood pressure if it is high and to keep your blood lipids (cholesterol) low.
• To detect any complications as early as possible. Treatment can prevent or delay some complications from becoming worse.
From: patient info