Medicines can replace what's missing
Sometimes a part of the body can't make enough of a certain substance, and this can make a person sick. When someone has type 1 diabetes, the pancreas (a body organ that is part of the digestive system) can't make enough of an important chemical called insulin, which the body needs to stay healthy. If your body makes too much of a certain chemical, that can make you sick, too. Luckily, medicines can replace what's missing (like insulin) or they can block production of a chemical when the body is making too much of it.