text: what is diabetes mellitus?condition?how is it treated?   the two major forms of diabetes are type 1, previously called insulin-dependent diabetes mellitus (iddm) or juvenile-onset diabetes, and type 2, previously called non-insulin-dependent diabetes mellitus (niddm) or maturity-onset diabetes.  diabetes mellitus is a group of diseases that share a common characteristic: high levels of blood glucose. diabetes happens when the body cannot produce enough insulin or when the insulin that is produced in the pancreas cannot work adequately. when diabetes is not well controlled, it can insulin is a hormone secreted by your pancreas and its function is to regulate blood glucose levels.   insulin works like a key to open the door of the cells so  glucose – the fuel you get from food - can come inside and be converted into energy.cause serious complications and premature death.  think of a corridor full of doors. you need a key to unlock each door so you can put glucose in each room, well, insulin is that key and if it is not produced in the right amounts or if it cannot open the doors because it is cracked, then glucose builds up in the blood causing your blood sugar to go up. this is called hyperglycemia (high levels of blood glucose) and is the common manifestation of diabetes.  the symptoms are:  frequent urination  excessive thirst  excessive hunger  feeling tired or ill  sudden weight loss  blurred vision  slow healing of infections  type 1 diabetes  in type 1 diabetes, the disease process is more severe than with type 2, and onset is usually in childhood:      * beta cells in the pancreas that produce insulin are gradually destroyed. eventually insulin deficiency is absolute.     * without insulin to move glucose into cells, blood glucose levels become excessively high, a condition known as hyperglycemia.     * because the body cannot utilize the sugar, it spills over into the urine and is lost.     * weakness, weight loss, and excessive hunger and thirst are among the consequences of this "starvation in the midst of plenty."     * patients become dependent on administered insulin for survival.   type 2 diabetes  type 2 diabetes is the most common form of diabetes, accounting for 90% of cases. an estimated 16 million americans have type 2 diabetes, and half are unaware they have it. the disease mechanisms in type 2 diabetes are not wholly known, but some experts suggest that it may involve the following three stages in most patients:      * the first stage in type 2 diabetes is the condition called insulin resistance. although insulin can attach normally to receptors on liver and muscle cells, certain mechanisms prevent insulin from moving glucose (blood sugar) into these cells where it can be used. most type 2 diabetics produce variable, even normal or high, amounts of insulin, and in the beginning this amount is usually sufficient to overcome such resistance.     * over time, the pancreas becomes unable to produce enough insulin to overcome resistance. in type 2 diabetes the initial effect of this stage is usually an abnormal rise in blood sugar right after a meal (called postprandial hyperglycemia). this effect is now believed to be particularly damaging to the body.     * eventually, the cycle of elevated glucose further impairs and possibly destroys beta cells, thereby stopping insulin production completely and causing full-blown diabetes. this is made evident by fasting hyperglycemia, in  which elevated glucose levels are present most of the time.  maturity-onset diabetes in youth. maturity-onset diabetes in youth (mody) is a rare genetic form of type 2 diabetes that develops only in caucasian teenagers. it accounts for 2% to 5% of type 2 cases.  gestational diabetes. an estimated 5% of pregnant women develop a form of type 2 diabetes, in their third trimester called gestational diabetes. gestational diabetes is usually temporary.