Diabetes mellitus is very common disease, these days. Earlier, it was very rare to find people suffering from diabetes mellitus; but now situation is such that it is very rare to find any family without, one old family member with diabetes mellitus. But, what happens in this disease and how many types it has? What are its causes and what are its symptoms? The answer to your each question, comes one by one.

First comes answer to first question, what happens in this disease, diabetes mellitus? The answer is, diabetes mellitus is a disease; in which blood glucose level, get distorted to increased level. But question is, why do it get distorted? It get distorted due to disturbance in either secretion of hormone insulin, which control blood glucose level and sometimes it occurs due to resistance, of peripheral tissues to hormone insulin. But, why do disturbance in secretion, of insulin or peripheral tissues's resistance to insulin occurs, in disease diabetes mellitus? The answer to this I will answer, but, before that first get answer to 2nd part of first question; asked in 2nd paragraph of article. 

And that question was, how many types it has? Well, answer to that is, diabetes mellitus has 2 types-

• First is- type 1 diabetes and 
• Second is- type 2 diabetes 

In first type, type 1 diabetes occurs due to, deficient secretion of hormone insulin. But, why do this occurs? This occurs because of dysfunction of pancreatic beta cell, which control hormone insulin secretion. In this, amount of hormone insulin required to control blood glucose level, is secreted very less and which is not sufficient to keep blood glucose level in normal limits and is not able to stop it; from going to increased level.

In 2nd type, type 2 diabetes, there is no such thing like disturbance in secretion of hormone insulin; on the opposite, there is some problem, in response of peripheral tissues to hormone insulin. And that problem is that they does not respond, to hormone insulin because of which, blood glucose level, keep on rising beyond normal limits. Now comes, answer to 1st part of question, what are its causes? Well, it has so many causes, which are-

1) The first one is- diseases inherited in genes from ancestors.

2) Second reason is- pancreatic beta cell dysfunction.

3) Third reason is- Peripheral tissues shows, resistance to hormone insulin.

4) No exercise schedule, on the opposite, more sitting schedule with fat rich diet. Obesity is the predisposing cause, which if not controlled at right time, can cause diabetes mellitus in future. High blood pressure and high cholesterol level. Past history of this disease during pregnancy, increases chances of suffering from it, in old age.

So that was about causes, now comes answer to 2nd part of 2nd question and that question was, what are its symptoms? Well, the symptoms of this disease are-

1) The first most known symptom of this disease is that with which its widely identified and that is, increased blood glucose level.

2) 2nd identification of this disease is, repeatedly going to toilet, to urinate at frequent short intervals.

3) Thirst for water and hunger for food is increased and even after good consumption of food, due to increased hunger; patient still feels tired and weak. Kidney does not work properly because they get deteriorated by this disease. This disease not only affect kidney function; but also affect your eye vision, going toward blurred vision stage. 

4) Gangrene of foot and not only that healing process of wounds, also get impacted. They does not heal timely. Their healing get delayed. That is reason, why minor wound of diabetes get turned into major in few days; just because of slow healing.