Diabetes is the inability to control the amount of sugar in the blood such that the level can go too high (hyperglycaemia). This makes you pass more urine (with sugar in it), thirsty and drowsy. At very high levels of blood sugar you can become unconscious (coma). Diabetes occurs when the body cannot produce enough of a hormone (insulin), and also when the body has a reduced response to the insulin that is produced. If not enough insulin is being produced (Type I diabetes), without insulin you die within months. Insulin was first isolated in 1921. If there is a reduced response to insulin (Type II diabetes) you do not have to be treated with insulin injections; blood sugar levels can sometimes be controlled just by diet and sometimes with tablets as well as diet. A problem of treatment is that it can sometimes cause the blood sugar to go too low (hypoglycaemia) which can also cause coma.
Apart from the day to day problems with the blood sugar level being unsatisfactory, people with both types of diabetes are prone to secondary problems (complications), which can be very disabling. Damage occurs to nerves and to blood vessels. You can get chronic or recurring ulcers on the feet and sometimes part of a leg has to be amputated. Eye disease caused by diabetes commonly causes blindness, and an important part of treatment is trying to prevent this. Having diabetes commonly also causes kidney damage which can lead to kidney failure.
Diabetes can cause or contribute to cardiovascular disease Map 451, but deaths due to those conditions are counted separately.
In 2002 Diabetes caused 2.6% of deaths in people over 60 years old and 1.8% of all deaths in rich territories. Diabetes caused 1.7% of all deaths worldwide in 2002, an average of 158 deaths per million people per year.