The most common symptoms of Type 1 Diabetes are the following:
Excessive thirst and a dry mouth
Frequent and abundant urination
Sudden weight loss
Lack of energy and extreme tiredness
With type 1 diabetes, the body’s immune system attacks part of its own pancreas. Scientists are not sure why. But the immune system mistakenly sees the insulin-producing cells in the pancreas as foreign, and destroys them. This attack is known as "autoimmune" disease.
T1D it’s also called insulin-dependent diabetes or “juvenile” diabetes, because type 1 diabetes usually develops in children and teenagers, though it can develop at any age.