Question

why are some patients of diabetes treated by giving injections of insulin?

Answer 1

Insulin reduces the blood sugar levels
Insulin helps your body use glucose (sugar) for energy And that's why some people with diabetes are insulin-dependent, which means they need to take it as medication. Taking insulin helps you control your blood sugar levels. 

Answer 2

Because diabetes is a condition in which the blood sugar level increases in a human's body due to lack of a hormone named insulin which is secreted by pancreas. And to control the blood sugar level Insulin is needed so giving injections of insulin can treat a diabetic patient.

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