1. Pre-Diabetes (Pre-Diabetes) Before developing type 2 diabetes, most people show symptoms of pre-diabetes, a condition in which blood glucose levels measure higher than normal but not as high as it does with diabetes. People with pre-diabetes – 79 Americans, or 35 percent of U.S. adults – face an increased risk of developing type 2 diabetes within a decade unless they change their eating habits and get more exercise. Research suggests that pre-diabetes may cause some damage to the body, especially the heart and circulatory system.   2. Type 1 Diabetes (Type 1) Type 1 diabetes (or insulin-dependent) develops when the immune system in the body attacks insulin-producing beta cells in the pancreas and destroys them. When the pancreas no longer makes insulin, blood glucose (blood sugar) cannot enter the cells to be used for energy, leaving high levels in the blood. Although type 1 is most often diagnosed in children and young adults under 30, people can develop type 1 at any age. An autoimmune reaction occurs that is caused by unknown environmental factors. The immune system attacks the beta cells of the pancreas, which produce insulin. People with type 1 cannot produced insulin and so are treated with injections of insulin. Modern medicine has advanced the care of people with type 1 diabetes with various insulins and other medicines, devices to test blood glucose (glucose meters), insulin pumps, and continuous glucose monitoring systems.   3. Type 2 Diabetes (Type 2) When the body does not produce enough insulin or does not use it properly or efficiently, type 2 diabetes (or insulin-resistant) develops. Insulin is the gatekeeper of the body that assures that blood glucose, or blood sugar, is handled properly. When the response to insulin in the body is ineffective, glucose builds up in the blood and accumulates. As diabetes develops, other health problems, such as high blood pressure and high cholesterol levels, are also likely to occur. Often, type 2 diabetes symptoms develop gradually, so people may have the disease for months or years before it is diagnosed. Most people who develop type 2 diabetes first exhibit signs of pre-diabetes, with blood glucose levels elevated but below the diabetes range. Type 2 diabetes is most often diagnosed in overweight adults age 40+ with a family history of diabetes, however, it is becoming increasingly common in younger people, especially adolescents. Recent research on obesity in children also indicates there is an increased risk of hybrid or double diabetes. People with type 1 diabetes who become overweight and have high blood pressure are at risk of developing type 2 as well. Also, certain racial and ethnic groups – African-Americans, Asian-Americans, Latinos and Native Americans – are more prone to diabetes.   4. Gestational Diabetes (Gestational Diabetes) During pregnancy, hormonal changes may cause impaired glucose tolerance and higher insulin needs. If the pancreas in a pregnant woman cannot keep up with the insulin needs, the blood glucose levels will rise above desired levels. Higher than normal blood glucose levels are harmful to the woman and her fetus. About 1 in 15 women develop gestational diabetes when pregnant.   5. Latent Autoimmune Diabetes of Adults (LADA) (LADA) Sometimes referred to as type 1.5 diabetes, Latent Autoimmune Diabetes of Adults (LADA) appears in adulthood, typically around age 30, and, like type 1 diabetes, is caused by an autoimmune attack on the insulin-producing cells of the pancreas. People with LADA are generally slim and physically fit with little or no resistance to insulin. LADA progresses more slowly than type 1 diabetes and can be misdiagnosed as type 2 diabetes because LADA patients sometimes respond well initially to oral medications. However, most patients eventually require insulin. Type 1.5 patients usually face a lower risk for heart problems than type 2 patients who have the characteristic high cholesterol and blood pressure.   6. Maturity-Onset Diabetes of the Young (MODY) (MODY) Some younger people develop Maturity-Onset Diabetes of the Young (MODY) – a genetically inherited, rare form of type 2 diabetes caused by a defect in a single gene. Diagnosed by both diabetes and genetic testing, MODY accounts for only one to five percent of diabetes cases. MODY patients – thin and usually in their teens or twenties – treat their disease with diet and, if necessary, with diabetes oral medications. The children of MODY patients face a one-in-two chance of themselves developing the condition.   7. Neonatal Diabetes Mellitus Neonatal Diabetes Mellitus (NDM) is a monogenic form of diabetes that occurs in the first 6 months of life. It is a rare condition occurring in only one in 100,000 to 500,000 live births. Infants with NDM do not produce enough insulin, leading to an increase in blood glucose. NDM can be mistaken for the much more common type 1 diabetes, but type 1 diabetes usually occurs later than the first 6 months of life. In about half of those with NDM, the condition is lifelong and is called permanent neonatal diabetes mellitus (PNDM). In the rest of those with NDM, the condition is transient and disappears during infancy but can reappear later in life; this type of NDM is called transient neonatal diabetes mellitus (TNDM). Specific genes that can cause NDM have been identified. Symptoms of NDM include thirst, frequent urination, and dehydration. NDM can be diagnosed by finding elevated levels of glucose in blood or urine. In severe cases, the deficiency of insulin may cause the body to produce an excess of acid, resulting in a potentially life-threatening condition called ketoacidosis. Most fetuses with NDM do not grow well in the womb and newborns are much smaller than those of the same gestational age, a condition called intrauterine growth restriction. After birth, some infants fail to gain weight and grow as rapidly as other infants of the same age and sex. Appropriate therapy improves and may normalize growth and development.   Other forms of diabetes mellitus include congenital diabetes, which is due to genetic defects of insulin secretion, cystic fibrosis-related diabetes, steroid diabetes induced by high doses of glucocorticoids, and several forms of monogenic diabetes.