Type 2 Diabetes: What It Is, Causes, Symptoms & Treatment

People living with type 2 diabetes face several significant health challenges.

The condition, which affects more than 10% of Americans, puts people at increased risk for debilitating medical issues like heart, kidney and eye damage, according to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

To help you get a handle on diabetes, this guide will explain what type 2 diabetes is, its key causes, symptoms to watch for and treatment options. It will also explain the difference between type 1 and type 2 diabetes.

What is type 2 diabetes?

A hormone called insulin, which is produced by your pancreas, is needed to help blood glucose (sugar) enter cells. There, glucose provides energy for numerous cellular functions, according to the NIDDK.

In type 2 diabetes, the cells have developed resistance to insulin, which causes the pancreas to produce more of it. When your pancreas can’t produce enough insulin to counter that resistance, glucose stays in your blood, and your cells don’t get enough energy.

Type 1 versus type 2 diabetes: What’s the difference?

Mayo Clinic endocrinologist Dr. Yogish Kudva noted in a clinic video that, while the exact cause of type 1 diabetes isn’t known, “we believe that it is an autoimmune disorder where the body mistakenly destroys insulin-producing cells in the pancreas.”

In type 2 diabetes, these insulin-producing cells aren’t destroyed. Instead, they don’t produce enough insulin to keep up with moving blood glucose into the cells due to insulin resistance.

Is type 2 diabetes genetic?

Genes play a role in the development of diabetes, according to the NIDDK. The institute was part of the largest diabetes genetics study to date in 2018, which was published in Nature Genetics. It involved nearly 900,000 participants and uncovered 400 additional gene markers associated with type 2 diabetes.

“The truth is that type 2 diabetes is more than one thing. It is common to describe it as a social and behavioral disease, and your chances of developing type 2 diabetes are much lower if you practice a healthy lifestyle,” said Dr. Jamil Alkhaddo, chief of endocrinology at the Allegheny Health Network in Canonsburg, Pa., in an interview for Highmark Health.

“That’s important -- it’s just not the whole story,” he continued. “Someone with multiple family members with diabetes is more likely to develop type 2 diabetes.”

What causes type 2 diabetes?

Type 2 diabetes is caused by multiple factors, according to the NIDDK, including:

• Insulin resistance
• Extra weight or obesity
• Lack of exercise
• Genes

In a study conducted over two decades and published in Nature Medicine, researchers estimated that 70% of type 2 diabetes cases worldwide were primarily linked to three unhealthy dietary choices: overconsumption of processed meat, overconsumption of refined rice and wheat, and underconsumption of whole grains.

Type 2 diabetes symptoms

Symptoms of diabetes may be mild or unnoticeable for many years, the NIDDK says. They include:

• Excessive thirst
• Increased urination
• Worsening vision
• Tingling and numbness in your hands and feet
• Sores that won’t heal
• Weight loss that you can’t explain
• Fatigue

Can type 2 diabetes be reversed?

“You can’t really cure diabetes, but there is such a thing as diabetes remission," Alkhaddo said in his 2022 interview. "If you’re able to get off all diabetes medication and keep your A1C in a good range for six months or more, we call that diabetes remission."

In a separate interview for Bayhealth in Dover, Del., endocrinologist Dr. Nira Madisi said type 2 diabetes can often be effectively managed. “It’s a condition that one has to live with every day, but making small changes can help,” she said.

Type 2 diabetes treatment

Alkhaddo pointed to three key factors.

“Diet, exercise and taking care of your mental health -- that’s the tripod,” he said.

He added that “these days, we have more medication options before we reach the stage of adding insulin, and many of the medications have a very promising impact.”

Besides different types of insulin, other type 2 diabetes medications work by helping with the production, release and absorption of insulin; by reducing the production of glucose, and by optimizing the use and release of glucose, according to the NIDDK and U.S. Food and Drug Administration.

Living with type 2 diabetes

For people living with diabetes type 2, Alkhaddo said regular blood sugar testing is a key to successful health outcomes.

Living with diabetes also means incorporating a few additional health-focused strategies into your daily routines. Madisi pointed to these as key:

• Following your medication schedule
• Minimizing sugar consumption
• Focusing on a type 2 diabetes diet rich in complex carbohydrates
• Fitting in 150 minutes of exercise per week
• Avoiding sitting for extended periods
• Losing excess weight
• Checking your feet regularly for wounds
• Managing your mental and emotional health

To learn more, check out the American Diabetes Association’s free Living with Type 2 Diabetes Program.