Diabetes Type 1 vs. Type 2: What are the Differences?


A published on Forbes, April 19, 2023

Diabetes is a widespread, chronic condition, impacting 34.2 million Americans. Under the diabetes umbrella are different types—including type 1 and type 2. While they share similar symptoms, there are crucial differences between the two, including the age groups that are commonly affected.

What Is Diabetes? 

Diabetes is a condition characterized by too-high levels of blood glucose, or blood sugar. This stems from a deficiency of insulin, the hormone that transforms glucose from the food we eat into energy.

Without insulin (or enough of it), glucose stays in the blood instead of getting into the body’s cells. This leads to symptoms of diabetes such as fatigue, increased appetite and thirst, frequent urination and slow-healing wounds. If untreated, diabetes can lead to serious health consequences such as heart disease, nerve damage and kidney disease.

Diabetes is diagnosed by blood tests ordered by a medical professional. Tests can include:

  • Fasting plasma glucose (FPG) tests measure your blood sugar levels at the exact moment of the test. The FPG test requires you to fast from food and drink for at least eight hours beforehand to get an accurate reading.
  • Random plasma glucose (RPG) tests are similar to FPG tests, but do not require fasting. Doctors usually order an RPG test if you already exhibit symptoms of diabetes.
  • A1C tests average your blood glucose levels over the previous three months. These tests do not require fasting. An A1C reading of 6.5 or higher indicates diabetes.

In addition to type 1 and type 2 diabetes, there is another type called gestational diabetes, which is when a person who does not already have diabetes first develops the condition during pregnancy.

Since type 1 diabetes means the body does not produce insulin on its own, treatment must be ongoing.


Type 1 Diabetes

In type 1 diabetes, the body’s immune system destroys the specialized cells in the pancreas that make and distribute insulin, causing the pancreas to stop making insulin altogether. Type 1 diabetes most often appears in children and young adults, and is much less common than type 2, with roughly 5% of people in the U.S. with diabetes having type 1. Type 1 diabetes cannot be prevented.

Common symptoms of type 1 diabetes are fatigue, increased urination, increased thirst and otherwise unexplained weight loss.

Causes of Type 1 Diabetes

While studies are still ongoing, experts think that type 1 diabetes may have several causes.

  • Certain genes determine a person’s risk of developing type 1 diabetes. Not everyone has these genes, but everyone with type 1 diabetes does. Even if none of your relatives has diabetes, there is a 1 in 300 chance of developing type 1 diabetes, according to diabetes research and treatment company TrialNet. For people who have a family member with type 1 diabetes, that number jumps to 1 in 20.
  • Environmental factors, such as viruses or cold climates, may activate the existing genes that predispose someone toward type 1 or alter a person’s gene expression to start inhibiting the production of insulin, leading to type 1 diabetes.

Type 2 Diabetes

Unlike type 1 diabetes in which your body does not make any insulin, type 2 diabetes occurs when the body becomes insulin resistant.Type 2 diabetes most often develops in middle-aged and elderly people, but people of all ages can develop it. Unlike type 1, type 2 diabetes can be prevented or reversed.

Symptoms of type 2 diabetes are slow to develop and are similar to those of type 1, but are milder if they present at all. Many people may not even notice symptoms.

Causes of Type 2 Diabetes

Type 2 diabetes is far more common than type 1; 90% to 95% of people with a diabetes diagnosis have type 2.  It can be caused by:

  • Genetic makeup. The risk of developing type 2 diabetes is higher if you have a relative with diabetes or if you are African American, Native American, Asian American or Hispanic/Latino.
  • Lifestyle and health problems. You can develop type 2 diabetes if you are physically inactive, obese or overweight. Other health issues such as high blood pressure, polycystic ovary syndrome (PCOS) and depression also increase the risk of type 2 diabetes.
  • Insulin resistance. The body may inherently be unable to use insulin well, but insulin resistance can also stem from pregnancy (called gestational diabetes), excess belly fat or being overweight. The pancreas may try to produce additional insulin in this case, but it’s often not enough to keep blood glucose levels down.

Photo by Mikhail Nilov