What Are The Differences Between Type 1 And Type 2 Diabetes?

Diabetes mellitus (also called diabetes) is a group of metabolic disorders caused by inappropriate glucose (blood sugar) regulation. According to the American Diabetes Association¹, approximately 37.3 million people in the US have diabetes, with 1.4 million new diagnoses each year. 

There are many subtypes of diabetes, the two most common being type 1 and type 2 diabetes.

Curious about clinical trials for Type 1 diabetes?

Researchers are studying thousands of new treatments and you could be a part of finding a cure while accessing the newest treatments for Type 1 diabetes.

Type 1 vs. type 2 diabetes

What is type 1 diabetes?

Type 1 diabetes is an autoimmune condition that destroys insulin-producing pancreatic cells. 

As a result, people with type 1 diabetes have a deficiency in a hormone called insulin, and if left untreated, it can result in abnormally high blood glucose levels (hyperglycemia).

It accounts for 5–10%² of all diabetes cases and can occur at any age³ in people of all races, shapes, and sizes. Although it used to be called “juvenile diabetes,” more adults actually live with type 1 diabetes than children. 

What is type 2 diabetes?

Type 2 diabetes mellitus or type 2 diabetes is the most common form of diabetes, characterized by insulin resistance and dysfunction of beta cells in the pancreas. 

It accounts for 90–95%² of all diabetes cases and is common amongst older populations. 

Early signs and symptoms

Both type 1 and type 2 diabetes share common symptoms, such as: 

  • Going to the toilet more frequently

  • Increased thirst

  • Increased hunger

  • Unexplained weight loss (although this is more common in type 1 diabetes)

  • Fatigue

  • Blurred vision 

Symptoms of type 1 diabetes can appear relatively quickly and, if left untreated, can lead to hospitalization and life-threatening complications.

Type 2 diabetes symptoms are easier to miss as they can develop without knowing until severe hyperglycemia symptoms occur. This is why it is crucial to know the early warning signs of diabetes, such as: 

  • Cuts, bruises, or sores that take longer to heal

  • Numb hands or legs

  • Nausea

  • Irritability

  • Repeated infections on the skin, genital areas, or in the mouth

Risk factors

Type 1 is predominantly influenced by a complex interaction between genetic and specific environmental factors⁴; whereas family history⁵, diet, and lifestyle are the major risk factors for type 2 diabetes.

Risk factors for type 1 diabetes include:

Genetic factors

You may be at risk of type 1 diabetes if you have an immediate family member with type 1 diabetes. This risk is higher if your father⁶ has type 1 diabetes.

Age

Type 1 diabetes is most common in children and young adults⁷, though it can occur at any age. 

Genetics

Certain gene types can increase your risk of type 1 diabetes by 30–50%⁸. 

Environmental Factors

If you carry certain high-risk genes, enterovirus infection, rapid weight gain in early life, and the balance of bacteria in the gut (microbiome) have been shown to increase your risk for developing type 1 diabetes.

Risk factors for type 2 diabetes include:

Family history

People with a family history of type 2 diabetes are two to six times⁹ more likely to develop type 2 diabetes.

Age

The risk of type 2 diabetes increases with age¹⁰ and is increasingly seen in children and teenagers.

Race

Type 2 diabetes is more prevalent in certain races¹¹, including Native American, Asian, African, Hispanic, and Latino populations. 

Weight

Overweight or obese individuals are two to five times more likely to develop type 2 diabetes.

Medical history

If you had a previous history of prediabetes, gestational diabetes (during pregnancy), high blood pressure, or polycystic ovary syndrome, you are more likely to develop type 2 diabetes.

Activity

Physical inactivity accounts for 7%¹⁰ of the current global type two diabetes burden. 

Diet

Certain foods and drinks have been linked with an increased risk of type 2 diabetes, e.g., processed meats, white bread, white rice, sweetened cereals, and sugary drinks. 

How does diabetes develop?

When you consume carbohydrates (starchy foods), they are digested in the intestinal tract and transported into the bloodstream, broken down into glucose. 

After eating carbohydrates, your blood glucose level rises, and your pancreas releases insulin¹², a hormone that helps move glucose into the cells for energy use and storage.

Insulin helps normalize blood sugar levels by absorbing glucose into the liver, where it is stored as energy, or into the muscle cells, which can be used as energy or stored for later use. 

Diabetes interferes with the body’s ability to process glucose and utilize insulin, so people with diabetes may find it difficult to regulate their blood glucose levels. The different types of diabetes also determine how insulin action and blood glucose levels are affected. 

Type 1 diabetes

If you have type 1 diabetes, there is an autoimmune response against the insulin-secreting cells in your pancreas. This means that your immune cells attack, damage, or destroy insulin-producing cells in the pancreas. 

As a result, your body cannot make enough insulin to maintain optimal blood glucose levels. 

The exact causes and triggers for developing type 1 diabetes are under investigation. Researchers believe that type 1 diabetes may be due to a complex interaction between genes and the environment. 

Type 2 diabetes

If you have type 2 diabetes, genetic, environmental, and lifestyle factors can prevent insulin from transporting glucose easily into the cells for energy production. This interference with insulin and glucose transport is referred to as insulin resistance. 

These same factors can also cause damage to the pancreas and decreased insulin levels in the body. The decreased insulin production by the pancreas and insulin resistance leads to less glucose being transported into cells for essential energy and higher levels of glucose circulating in the bloodstream. 

If left untreated, both types of diabetes can lead to severe hyperglycemia. This can increase your risk of diabetes-related complications. 

Type 1 and type 2 diabetes complications

Type 1 and type 2 diabetes are associated with numerous acute and chronic complications. 

Diabetic ketoacidosis (DKA)

Diabetic ketoacidosis is a common life-threatening complication of type 1 diabetes. When the body cannot produce insulin, glucose can no longer be transported into cells for energy, and the body has to rely upon alternative energy sources such as ketones. 

When ketones build up in the body over and above normal levels, this causes the blood to become more acidic. Common symptoms of DKA include frequent urination, increased thirst, increased or decreased appetite, nausea, vomiting, fatigue, lethargy, and abdominal pain. 

One of the most distinctive physical signs of DKA is a ‘fruity’ or acetone-scented breath (although this can be difficult to identify in some cases). 

Nerve damage

Diabetic neuropathy, or nerve damage, is a serious complication affecting both types of diabetes. Symptoms are gradual and can vary depending on the person and the type of nerve damage. 

Common symptoms of diabetic neuropathy can include numbness, tingling, pain, and weakness. 

Diabetes can lead to several types of nerve damage, such as: 

  • Peripheral neuropathy affects nerves outside the brain and spinal cord. Common areas include the hands and feet.

  • Proximal neuropathy affects nerves in the hips, buttocks, and thighs.

  • Focal neuropathy affects single nerve fibers. The head, torso, hand, or leg/foot are commonly affected.

  • Autonomic neuropathy affects nerves that regulate non-voluntary functions such as blood pressure, heart rate, sweating, and digestion. 

Eye damage

Chronic hyperglycemia can cause damage to blood vessels in the retina, a light-sensitive tissue at the back of the eye.

This is also known as diabetic retinopathy. In its early phases, people may not show any symptoms. However, as the disease progresses, it can lead to more serious complications, such as changes in vision, eye swelling, ruptured blood vessels, and even blindness.

Heart damage

Diabetes is a significant risk factor for heart conditions such as coronary artery disease, heart attack, and stroke.

The risk of dying from heart disease and stroke is two to four times higher¹³ for people with diabetes.

Diabetes can also lead to a condition known as diabetic cardiomyopathy¹⁴. This is when there is severe damage to the heart muscle without high blood pressure or the narrowing of major blood vessels. The exact mechanism of how diabetes causes this condition is currently under investigation.

Kidney damage

Also known as diabetic nephropathy, kidney damage in people with diabetes is the leading cause of chronic kidney disease and accounts for 44%¹⁵ of new cases of kidney failure. 

As the condition progresses, people may complain of symptoms including fatigue, swollen feet, and ‘foamy’ urine. 

What is the worst type of diabetes?

Research in both fields has provided valuable insights highlighting the severity of type 1 and type 2 diabetes.

Both types of diabetes share similarities, such as: 

  • Both are common types of diabetes

  • Both are affected by the body’s ability to produce and use insulin

  • Both share similar symptoms and complications 

The experience of type 1 and 2 diabetes can differ from person to person and on factors such as family history, genetics, geography, and the type of medical care you can access. Diabetes can also lead to emotional, psychological, and financial stress. Since diabetes impacts people in so many ways, there is no clear answer as to which diabetes is the worst. 

How do you diagnose type 1 and type 2 diabetes?

Your doctor or other healthcare professional can run blood tests to determine if you have diabetes. Sometimes, a series of tests may be required to determine if you have diabetes.

Commonly used tests for diagnosing type 2 diabetes include:

Fasting plasma glucose (FPG)

This test checks your blood glucose level at a single point in time after you've been fasting for at least eight hours.

FPG results and their meaning are as follows:

  • 99 mg/dl (5.5 mmol/L) or below: Normal glucose levels

  • 100 mg/dl to 125 mg/dl (5.6 to 6.9 mmol/L): Indicates prediabetes

  • 126 mg/dl (7.0 mmol/L) or higher: Indicates diabetes

Hemoglobin A1C test

This test provides a measure of your blood glucose levels over the two to three months before having the test. 

Your blood glucose levels will be analyzed based on hemoglobin, an oxygen-carrying protein in your bloodstream. This is then reported as a percentage, where a higher percentage indicates higher blood sugar levels. 

Although the HbA1c is not the most reliable test for diagnosing diabetes, it can be convenient for some people because there is no need to fast beforehand.

Please note that some Southern Asian, Mediterranean, and African people can show falsely high or low results due to their genetic variation. Medical conditions that affect hemoglobin (Hb) in the blood can also make the HbA1c result unreliable.

The International Expert Committee¹⁶ recommends the following classifications be made based on two repeat HbA1c tests:

Random plasma glucose test (RPG)

RPG tests check for blood glucose levels, regardless of when you last ate, and provide a snapshot of your blood sugar status. Healthcare providers consider this test when they want to determine your blood sugar levels without fasting.

A reading of 200 mg/dl (11.1 mmol/L) or above shows that you have diabetes.

Oral glucose tolerance test (OGTT)

The oral glucose tolerance test is a two-hour test that shows your doctor how your body processes glucose (sugar).

After you have fasted for eight to ten hours (you may be allowed water), your healthcare provider will take some blood to determine your fasting blood glucose level. They will then give you a drink containing a specific amount of glucose, and you will have another one to two blood draws, with the second draw two hours after finishing the glucose drink.

OGTT results and their meaning:

  • 139 mg/dl (7.7 mmol/L) or below: Normal glucose levels

  • 140 mg/dl to 199 mg/dl (7.8 to 11.0 mmol/L): Indicates prediabetes

  • 200 mg/dl (11.1 mmol/L) or higher: Indicates diabetes

Treatment

Treatments are available for type 1 and type 2 diabetes. These are long-term treatments that are manageable with the help of your healthcare team and by frequently monitoring your blood glucose levels. 

People with type 1 diabetes will need to try and keep their blood glucose as close to normal as possible by using lifelong insulin therapy. This can be delivered as an injection multiple times a day or through a continuous insulin pump device. 

There are several types of insulin available. Some are short-acting, and others are intermediate or long-acting. Your doctor may prescribe a combination of different insulin types.

To determine which types of insulin and which doses you need, your doctor will consider factors such as your blood glucose levels over the course of the day and your home and work commitments.

The current options for giving yourself insulin are:

  • Insulin injections: Insulin can be injected into the fatty tissue just below your skin (the subcutaneous tissue) with a needle and syringe or a pen-like device.

  • Insulin pump: An insulin pump delivers a steady dose of insulin into the subcutaneous tissue via a very thin tube inserted through the skin. Several different types of insulin pumps are available, and many now operate with a continuous glucose monitoring (CGM) device. 

There is also an inhaled, rapid-acting insulin called Afrezza available in some countries.

  • New insulin-delivery systems are currently developing, e.g., insulin patches and implanted devices. Advances in gene and stem cell¹⁷ therapies will provide us with even more treatment options in the future.

Treatment strategies for people with type 2 diabetes include changing diet, level of physical activity, and medications¹⁸. Several medications are now used to treat type 2 diabetes which also helps decrease the risk of diabetes-related complications.

Insulin therapy may also be prescribed for type 2 diabetes if lifestyle changes and other medications don't adequately reduce blood glucose levels.

Diabetes treatments play an important part in preventing major complications, so discussing your options with your doctor is important. 

Management

For type 1 diabetes and people with type 2 diabetes who take insulin, frequent self-monitoring of blood sugar levels is essential. This will help you and your healthcare professional adjust your insulin dosages accordingly. 

Your doctor will advise you on when to measure your blood glucose levels and how to go about this. You may need to check your blood glucose levels before or after meals, during exercise sessions, or even overnight. 

Glucose monitoring can be done via finger prick testing with a glucose meter (using blood glucose test strips) or a continuous glucose monitoring (CGM) device. The CGM device has sensors placed under the skin to monitor your glucose every few minutes.

The information is transmitted to a mobile device such as your phone and sends alerts when your glucose levels are too high or too low.

  • Based on your blood glucose readings, you can determine if you need to take action to keep your blood glucose levels within the healthy range set by your doctor. Your diabetes health care professionals will also be able to review your blood glucose levels over time to determine if you need to make changes to your treatment plan.

Additional ways to manage your diabetes include: 

  • Eating a well-balanced diet

  • Regularly taking medication

  • Getting annual checkups for diabetes-related complications

  • Incorporating physical activity into your daily routine

  • Finding a local diabetes support group

  • Minimizing stress levels

Prevention

Currently, type 1 diabetes cannot be prevented as it is not known what causes this autoimmune condition.

Adjusting your diet and exercise routine may reduce your risk of type 2 diabetes. Other ways to lower your risk include:

  • Maintaining steady blood pressure

  • Management of cholesterol levels

  • Quitting smoking

  • Reducing alcohol intake 

The lowdown

Type 1 and type 2 diabetes can occur when the body has problems with insulin which affect the way glucose is stored and used. Type 1 diabetes is an autoimmune condition that usually develops early in life. In contrast, type 2 diabetes is due to several factors, including family history, medical history, and lifestyle factors.

There is currently no known cure for type 1 or type 2 diabetes, although researchers worldwide are working hard to find one.

By working closely with your doctor and the other members of your diabetes healthcare team, you can help design a treatment plan that suits your individual needs.

Lifestyle changes, monitoring, and medication can all help to improve your diabetes and quality of life.

Curious about clinical trials for Type 1 diabetes?

Researchers are studying thousands of new treatments and you could be a part of finding a cure while accessing the newest treatments for Type 1 diabetes.

Discover which clinical trials you are eligible for

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Have you taken medication for Type 1 diabetes?
Have you been diagnosed with Type 1 diabetes?

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