Can you explain the difference between type I and type II diabetes?

Both types of diabetes are based around the hormone insulin. Insulin is produced by the pancreas when we have elevated levels of glucose in the blood, for example after eating a meal. Insulin binds to receptors at cell membranes signalling that the cell should take up glucose from the blood. Therefore, insulin is very important in controlling our blood sugar levels. Type I diabetes results from the pancreas being unable to produce insulin. It usually develops earlier in life. Patients depend on insulin injections in managing their condition. They inject insulin in to their bodies after eating a meal so that their cells are signalled to take up glucose from the blood. Type II diabetes is different. Type II is caused by the failure of the body to respond to insulin - the pancreas makes and secretes insulin but cells cannot sense and respond to it. Therefore, cells fail to take up glucose from the blood. This condition develops later in life and is strongly correlated with obesity. Patients can manage type II diabetes with exercise and good diet, particularly with the aims of losing fat and gaining muscle. To summarise in one sentence, type I is caused by failure to produce insulin whereas type II is caused by the failure of cells to respond to insulin.