"Can diabetes be deadly?"

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What is diabetes?
Diabetes is a disease that occurs when your blood glucose, also called blood sugar, is too high. Blood glucose is your main source of energy and comes from the food you eat. Insulin, a hormone made by the pancreas, helps glucose from food get into your cells to be used for energy. Sometimes your body doesn’t make enough—or any—insulin or doesn’t use insulin well. Glucose then stays in your blood and doesn’t reach your cells.source
Over time, having too much glucose in your blood can cause health problems. Although diabetes has no cure, you can take steps to manage your diabetes and stay healthy.

Sometimes people call diabetes “a touch of sugar” or “borderline diabetes.” These terms suggest that someone doesn’t really have diabetes or has a less serious case, but every case of diabetes is serious. I learned this from my mom who is suffering from the disease, together with some other health challenge, such as Asthma and others. She could survive these health Issues through proper medication.

]The broad differences in treatment between the two types are:

Type 1 diabetes is treated with insulin injection. Careful diet and activity planning is needed to avoid complications of treatment.
Type 2 diabetes is treated with lifestyle measures, drugs taken by mouth, and sometimes also insulin if the other treatments fail.

Medications for type 1 diabetes

Treatment for type 1 diabetes is always with insulin, to replace the body's absent insulin and keep blood sugar levels under control.

A woman injects insulin into her stomach.
Type 1 diabetes is always treated with insulin. Many patients inject insulin themselves.
Insulin treatments

Insulin is usually given by injection - by patients themselves, injecting it under the skin, or if hospitalized, sometimes directly into the blood. It is also available as a powder that patients can breathe in.

Insulin injections vary by how quickly they act, their peak action, and how long they last. The aim is to mimic how the body would produce insulin throughout the day and in relation to energy intake.

Medications for type 2 diabetes

Two glucometers and some diabetes medication.
People with type 2 diabetes will only use insulin when other treatments haven't worked.
Insulin can also be used to manage high blood glucose levels in type 2 diabetes, but only when other treatments have failed to work. Women with type 2 diabetes who become pregnant may also use it to reduce effects on the fetus.

In people who still have high blood glucose levels in spite of lifestyle measures, non-insulin drugs to lower blood glucose levels can be prescribed. These drugs are taken by mouth and listed below.

Many of the drugs are combined for more than one effect. If two or more treatments are needed to control glucose levels, insulin treatment may become needed.

diabetes can be deadly?

diabetes is a disease which makes the body unable to control blood sugar levels. The high blood sugars of diabetes can be deadly in many different ways. First, people that allow their blood sugars to get too high can suffer from a diabetic coma. This usually occurs when someone that has diabetes doesn't take their medications. Diabetes is associated with many other diseases that can be deadly. People with diabetes are much more likely to have heart attacks than those without diabetes. The same is true for strokes. Finally, people with diabetes are more likely to have kidney disease. In fact, the most common cause of kidney failure requiring permanent dialysis is diabetes. There are two things you can do to help prevent these from happening. First, you should focus on losing weight. If you lose weight, you will reduce your chances of getting diabetes. In addition, exercise (whether you lose weight or not) can really help your metabolism. Finally, you should get screened for diabetes yearly. Diabetes can often be present without any symptoms. The best physician for you to see about this problem is your primary care physician. He or she can perform your yearly test and council you on how to avoid getting diabetes.
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Reference; Wikipedia