Short-term complication - a very high blood glucose level
This is not as common with Type 2 diabetes as in Type 1. However, if the Type 2 diabetes goes untreated or undiagnosed, very high glucose levels can occur. High levels of blood glucose can cause dehydration, drowsiness and serious illness which can be life-threatening.
If the blood glucose level is higher than normal over a long period of time, it can gradually damage the 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 first developing diabetes).
The type and severity of long-term complications vary from case to case. Some patients might not develop any complications. In general, the nearer the blood glucose level is to normal, the less risk there is of developing complications. The risk of developing complications is also reduced if any 'risk factors' are dealt with e.g. high blood pressure.