Diabetes is disease in which body does not make any insulin, or enough insulin or is not able to use insulin effectively or both.Insulin is produced in the body by an organ called pancreas.Pancreas has clusters of cells scattered though out it called islet of Langerhans.These contain cells called Beta cells.These cells produce insulin, a hormone, in response to glucose in blood.Glucose is another name for sugar.When glucose level goes above a certain level and remains persistently elevated, ( hyperglycaemia ),it is known as Diabetes.
There are several types of diabetes but two are main,diabetes type 1 and diabetes type 2.There is another type called Gestational diabetes which occurs during pregnancy.There are also other types of diabetes which will not be discussed here.
Type 1 diabetes,also known as juvenile or insulin dependent diabetes is caused by lack of insulin due to lack of insulin.No insulin or very little insulin is produced as insulin producing beta cells in pancreas are destroyed.Why this happens it not clearly understood but there are certain theories which tries to explain this .
(1) Autoimmune disease -there is is a defence mechanism working in the body ,our immune system,which normally protects body from infections by identifying and destroying bacteria, viruses and other potentially harmful foreign substances.But in autoimmune disease the immune system attacks bodys own cells,in this case beta cells of pancreas and destroying it completely.How it first starts and why is not understood completely.
(2)Viruses -several including mumps virus have been implicated.Rsearchers say that viruses have protein on them.These proteins are identifies as foreign body by our immune system and attacked,the process is extended to beta cells which are also destroyed.
(3)in susceptible persons ie.persons prone to develop diabetes insulin also acts as feign body inviting our own immune system to destroy it.
(4) Environmental Factors -allergy to cows milk in early infancy,vit.D insufficiency,gluten of cereals etc are all implicated.
researches are going on and nothing is conclusive.
Beta cell destruction may take place over several years, but symptoms of disease usually appear over a short period. Type 1 typically occurs in children and young adults.
Its importance lies in the fact that there is a spurt in incidence of type 1 worldwide.