COVID-19 (Coronavirus) Update

Loyola Medicine is resuming select health care services. Learn more about resumption of services.

Patient receiving blood glucose test by doctor.

What is Diabetes and Who Gets It?

November 17, 2017

Loyola Medicine primary care physician Naaz Aziz, MDNaaz Aziz, MD

Diabetes is a group of diseases that result in too much sugar in the blood. To answer what causes diabetes, it is important to understand the role of insulin in your body. When you eat, your body turns food into sugars, or glucose. At that point, your pancreas is supposed to release insulin. Insulin serves as the “key” to open your cells and let the glucose enter. This allows you to use the glucose for energy. But with diabetes, this system does not work.

There are four kinds of diabetes: type 1, type 2, gestational diabetes and pre-diabetes. Types 1 and 2 come about in different ways and have different risk factors. Both gestational diabetes and pre-diabetes may lead to type 2 diabetes.

Type 1 Diabetes

Type 1 diabetes is sometimes called “juvenile diabetes” because it usually develops in children and teenagers, though it can start at any age. About 5 percent of diabetes cases are type 1.

With type 1 diabetes, the body's immune system attacks part of its own pancreas. The immune system sees the insulin-producing cells in the pancreas as foreign and destroys them. This attack is known as “autoimmune” disease.

We don’t know what causes type 1 diabetes, but people who have certain genes are at more risk of developing it.

Here is how type 1 diabetes happens:

  • The pancreas’ insulin-producing cells, called islets, are the ones that sense glucose in the blood and, in response, produce the amount of insulin needed to make blood sugars normal.
  • Because the islet cells are destroyed by the immune system, there is no insulin.
  • With no insulin, sugar builds up in the blood.
  • The body's cells starve from the lack of glucose.
  • If the disease isn’t treated, the high level of blood sugar can damage eyes, kidneys and nerves. It also can lead to coma and death.
  • People with type 1 diabetes take insulin injections. How much insulin a patient needs is based on many factors, including food, exercise, stress, emotions and general health.

Currently, type 1 diabetes cannot be prevented, though researchers are trying to find what may trigger the disease in some people who have the genes and not others.

Type 2 Diabetes

Type 2 diabetes is the most common form of diabetes. Often type 2 is tied to people who are overweight and have a sedentary lifestyle. People with type 2 diabetes are able to produce some of their own insulin, but it's not enough. Sometimes, the insulin does not work and the cells will not allow the glucose to enter. This is called insulin resistance.

Treatment focuses on diet and exercise. If blood sugar levels are still high, oral medications are used to help the body use its own insulin more efficiently. In some cases, insulin injections are necessary.

In type 2 diabetes, prevention is a priority if you are at increased risk of diabetes, such as if you are overweight or have a family history of the disease, especially if a parent or sibling has it.

It is never too late to make the big step toward preventing diabetes. Making a few simple changes in your lifestyle now may help avoid serious health complications. Prevention includes regular physical activity, eating plenty of fiber and more whole grains, losing extra weight, and making healthier eating choices. You should make variety and portion control part of your healthy eating plan.

Gestational Diabetes

Gestational diabetes is a form of high blood sugar affecting pregnant women. Those who develop gestational diabetes are at higher risk of developing type 2 diabetes later in life. Steps for preventing it are the same as those for preventing type 2 diabetes.


Pre-diabetes is a condition in which the blood sugar is high, but not high enough to be called type 2 diabetes. Without intervention, if you have pre-diabetes, you are likely to have type 2 diabetes within 10 years.

Many people with pre-diabetes have no symptoms, but there may be signs. If diabetes runs in your family and you are overweight, your primary care provider may order blood tests to check the level of sugar present. If the numbers reach a certain level, you may have pre-diabetes and will be given next steps to prevent your blood sugar from getting higher and, hopefully, to bring them down to normal levels.

Progression from pre-diabetes to type 2 diabetes is not inevitable. With lifestyle changes, weight loss and medicine, it is possible to bring blood glucose levels back to normal and keep them there.


While pre-diabetes and gestational diabetes usually do not cause noticeable symptoms, type 1 and type 2 diabetes share some signs, including:

  • Urinating often
  • Feeling very thirsty
  • Feeling very hungry, even when you are eating
  • Feeling extreme tiredness
  • Having blurry vision
  • Having cuts and bruises that heal slowly
  • Losing weight even if you are eating more*
  • Feeling tingling, pain or numbness in the hands or feet**
        *More common for type 1
      **More common for type 2

If you or a family member is experiencing signs or possible symptoms of diabetes, a family medicine doctor or another primary care physician can assist with diagnosing the disease and creating a treatment plan. Loyola Medicine also has a diabetes care center.

Naaz Aziz, MD, is a family medicine physician who treats adults and children. She has a special clinical interest in diabetes, preventive medicine and asthma. Dr. Aziz sees patients in Melrose Park at the Loyola Center for Health at Gottlieb.

The American Diabetes Association offers information on the different types of diabetes, including gestational, a type 2 risk test, a pre-diabetes test and resources about treatment and living with the disease.