Diabetes is a disease in which the body's blood glucose, or blood sugar, levels are abnormally elevated. The body uses glucose as energy, and glucose normally circulates in the blood stream, ready to enter cells if the cells need energy. Insulin is a natural substance in the body that facilitates the entry of glucose into cells. When there is too little insulin, or the body does not respond normally to insulin, the result is diabetes. There are three main types of diabetes: type 1, type 2 and gestational, each of which has distinct causes.
Autoimmunity
The purpose of the body's immune system is to attack foreign microbes, such as viruses and bacteria, when these foreign invaders infect the body. The Mayo Clinic reports that type 1 diabetes, which is also called insulin-dependent diabetes, is caused by an inappropriate immune response. In people with type 1 diabetes, the immune system attacks the pancreas, the organ that makes insulin. The body then does not have enough insulin to facilitate the entry of glucose into the cells. Every time a person eats, especially sugar and/or carbohydrates, his blood glucose rises. For persons with type 1 diabetes, the blood glucose remains high because there is no way for the glucose to get into the cells. Type 1 diabetes is often treated with injections of insulin to supply the insulin the body is unable to make.
Insulin Resistance
The most common form of diabetes is type 2 diabetes, according to the National Diabetes Information Clearinghouse, a service of the National Institutes of Health. The cause of type 2 diabetes is distinctly different from the cause of type 1 diabetes. The pancreas of a person with type 2 diabetes is still able to produce insulin; however, the cells become resistant to the effects of insulin and thus the cells do not absorb glucose out of the blood normally. The pancreas responds by making more of this essential substance, but the body often cannot keep up with the body's demand for insulin. Being overweight and inactive greatly increases the risk of insulin resistance.
Pregnancy Hormones
Gestational diabetes affects some women temporarily during the latter portion of a woman's pregnancy. According to the International Diabetes Foundation, gestational diabetes affects 2 to 5 percent of all pregnant women. Though the exact cause of gestational diabetes is not certain, the American Diabetes Association indicates that scientists do have some idea. Research has shown that the hormones produced by the mother during pregnancy act to block the effect of insulin, effectively causing insulin resistance. The result is that the body needs much more insulin to behave normally, and the body often cannot keep up with this demand. Left untreated, the extra blood glucose crosses the placenta and elevates the fetus's blood glucose. The extra energy is transferred into fat in the baby's body, possibly making the baby overweight while still in the uterus. The extra fat puts the baby at risk for some health problems, including breathing problems and risk of injury during the birthing process.
