The Differences (and Similarities) Between Type 1 and Type 2 Diabetes

Type 1 and type 2 diabetes may share a name, but there are as many things different about them as there are similarities.

At their core, both diseases involve abnormally high levels of sugar in the bloodstream, which is a dangerous, if not life-threatening, situation. Blood sugar changes occur as a result of deficiencies in the hormone insulin.

Typically, insulin, which is produced by your pancreas, heads to the bloodstream after you eat. Its purpose is to break down the sugars from food before escorting them into your cells, where they wait to be used as energy.

In type 1 diabetes, the body no longer makes any insulin at all, which means that blood sugar levels rise to sometimes stratospheric levels in the blood.

But type 2 diabetes is a completely different physiology, with the insulin getting less and less effective over time, rather than shutting down abruptly, Mary Vouyiouklis Kellis, MD, an endocrinologist at the Cleveland Clinic, told Health. These issues with insulin are known as insulin resistance.

Here's more about how different and similar type 1 and type 2 diabetes are to one another.

What Makes Type 1 and Type 2 Diabetes Different?

There are a few components of type 1 and type 2 diabetes that make them differ.

Only Type 2 Diabetes Can Be Prevented

There's no way to prevent type 1 diabetes, but you can help prevent type 2 with lifestyle modifications.

"We're talking about making healthier food choices, engaging in physical activity, and taking medication," Jasmine D. Gonzalvo, PharmD, director of the Center for Health Equity and Innovation at Purdue University in West Lafayette, Indiana, told Health.

Specific ways to help prevent or delay type 2 diabetes include:

• Setting a weight loss goal
• Following a healthy eating plan
• Finding ways to move more
• Tracking goal progress
• Consulting a healthcare team
• Getting support for your lifestyle changes

Their Causes Are Different

Type 1 diabetes is an autoimmune condition, which means your immune system mistakenly attacks your body. In the case of type 1 diabetes, immune-system cells go after the insulin-producing cells in the pancreas, which causes insulin production to turn off suddenly. However, it is unclear why the immune system reacts this way.

"We don't completely understand why this happens, but there is some data that a viral infection can trigger the process if you already have a predisposition," said Dr. Vouyiouklis Kellis. "You may already have antibodies [the immune-system cells that attack the pancreas], but the second hit is a viral infection." Beyond viral infections, genetics may also play a role in type 1 diabetes.

With type 2 diabetes, genetics, including family history, can also play a role along with insulin resistance. Still, the main risk comes from being obese or overweight, as well as other lifestyle factors, such as not being active and eating unhealthy foods, said Gonzalvo.

The Initial Diagnosis for Type 1 and Type 2 Diabetes Typically Occurs in Different Populations

Children and young adults are normally diagnosed with type 1 diabetes. The opposite is the case for type 2 diabetes in general. Type 2 diabetes mostly affects adults.

Other distinctions remain as well. "Type 1 diabetes tends to be diagnosed in younger individuals of normal weight, though they may have a personal or family history of autoimmune disease," Deena Adimoolam, MD, a specialist in endocrinology and preventative medicine, who practices in New Jersey, told Health. "Type 2 diabetes tends to be diagnosed in older individuals who are overweight or obese."

Insulin Is Always Required for Individuals With Type 1 Diabetes

There's only one treatment for type 1 diabetes: insulin replacement. "Without insulin, people with type 1 diabetes may die from complications like diabetic ketoacidosis," said Dr. Adimoolam. There are different ways that an individual can take insulin. Some of the common methods include:

• A needle and syringe
• An insulin pen
• An insulin pump
  

Of note, there are also different types of insulin a person with diabetes can take, ranging from rapid-acting to ultra-long-acting. A healthcare provider will determine which options are appropriate for you.

What Makes the Two Conditions Similar?

Though they may have their differences, there are ways that type 1 and type 2 diabetes are similar.

They Are Diagnosed in a Similar Manner

Although type 1 and type 2 diabetes are typically diagnosed in different age ranges, both can be diagnosed at any time. Additionally, diagnosing type 1 and type 2 diabetes is based on blood tests to determine how high your blood sugar is as well as which type of diabetes you may have. The tests that may be used may be:

• A1C test: Looks at your average blood sugar levels over the past two to three months
• Fasting plasma glucose test: Measures levels after you've been fasting for at least eight hours
• Random plasma glucose test: Measures levels without an eight-hour fast

If a healthcare provider thinks you have type 1 diabetes, they may order certain antibody tests.

They Share Similar Symptoms and Complications

Consistently high levels of blood sugar cause the symptoms of both types of diabetes, and many of those symptoms are the same.

"Presenting symptoms are similar in all forms of diabetes—increased thirst, increased urination, blurred vision, worsening fatigue, weight loss," said Dr. Adimoolam. "Since patients with type 1 diabetes produce very little or no insulin at the time of diagnosis, they are more likely to present to the hospital with a life-threatening condition called diabetic ketoacidosis (DKA)."

One unique symptom of type 2 diabetes is a condition called acamphotisi nigricans, explained Dr. Vouyiouklis Kellis. That's when you see a darkening of the skin at the back of the neck or back of the arm, places where there are folds under the skin. This skin condition is a sign of insulin resistance, which is a hallmark of type 2 diabetes but not type 1 diabetes.

Chronically high levels of blood glucose can lead to serious complications, which are similar for both types of diabetes, according to Dr. Adimoolam. These include heart disease, kidney problems, nerve damage, foot problems, and eye problems.

Type 1 and Type 2 Diabetes Are Managed Similarly

A healthy diet and regular exercise are a cornerstone of managing both forms of diabetes. Other methods of management include:

• Monitoring blood glucose levels
• Having blood pressure and cholesterol under control
• Taking prescribed medicines
• Working with a healthcare team
• Finding healthy ways to cope with having diabetes (e.g., yoga, support groups)
  

A Quick Review

Type 1 and type 2 diabetes, at their foundation, are conditions of having high blood sugar. They have a number of differences (e.g., causes and the ability to prevent type 2 diabetes) and similarities (e.g., symptoms and diagnostic testing). Ultimately, talking with a healthcare provider can be helpful for determining treatment, and both conditions can be managed similarly.