Diabetes
Diabetes is a condition in which a person has a high blood sugar (glucose) level, either because the body doesn't produce enough insulin, or because body cells don't properly respond to the insulin that is produced. Insulin is a hormone produced in the pancreas which enables body cells to absorb glucose, to turn into energy. If the body cells do not absorb the glucose, the glucose accumulates in the blood (hyperglycemia), leading to vascular, nerve, and other complications. Diabetes mellitus is a chronic disease which is difficult to cure.
There are many types of diabetes:
Type 1
This type of diabetes is results from the body's failure to produce insulin, and presently requires the person to inject insulin.

Type 2
This type is results from insulin resistance, a condition in which cells fail to use insulin properly, sometimes combined with an absolute insulin deficiency.

Gestational diabetes
This type is when pregnant women, who have never had diabetes before, have a high blood glucose level during pregnancy.

Congenital diabetes
This type is congenital diabetes, which is due to genetic defects of insulin secretion.

Steroid diabetes
This induced by high doses of glucocorticoids. Typical medical conditions in which steroid diabetes arises during high-dose glucocorticoid treatment include severe asthma, organ transplantation, cystic fibrosis, inflammatory bowel disease, and induction chemotherapy for leukemia or other cancers

Treatments
Type 1
diabetes risk is known to depend upon a genetic predisposition based on HLA types (particularly types DR3 and DR4), an unknown environmental trigger (suspected to be an infection, although none has proven definitive in all cases), and an uncontrolled autoimmune response that attacks the insulin producing beta cells.

Type 2
diabetes risks can be reduced in many cases by making changes in diet and increasing physical activity. Gestational diabetes: The goal of treatment is to reduce the risks of GDM for mother and child. Scientific evidence is beginning to show that controlling glucose levels can result in less serious fetal complications (such as macrosomia) and increased maternal quality of life. Unfortunately, treatment of GDM is also accompanied by more infants admitted to neonatal wards and more inductions of labour, with no proven decrease in cesarean section rates or perinatal mortality. These findings are still recent and controversial.

Congenital diabetes
The treatment is insulin therapy.

Steroid diabetes
Treatment depends on the severity of the hyperglycemia and the estimated duration of the steroid treatment. Mild hyperglycemia in an immunocompetent patient may not require treatment if the steroids will be discontinued in a week or two. Moderate hyperglycemia carries an increased risk of infection, especially fungal, and especially in people with other risk factors such as immunocompromise or central intravenous lines. Insulin is the most common treatment