Type 1 diabetes occurs when the immune system attacks pancreatic beta cells. Type 2 diabetes happens when the body cannot use insulin effectively. The two types differ in symptoms, causes, and treatment.
Diabetes occurs when the body cannot properly store or use glucose (sugar) and, as a result, glucose builds up in the blood instead of reaching the cells.
Type 1 diabetes often appears in children or adolescents. This condition occurs when the immune system attacks insulin-producing pancreatic cells.
Type 2 diabetes is more common in adults but can occur in children. It results from the body’s inability to effectively use insulin. Lifestyle factors contribute to the development of this condition.
Both types can cause complications such as cardiovascular disease, kidney damage, vision loss, and nerve issues. This article explores the similarities and differences between type 1 and type 2 diabetes.
A person with diabetes might experience symptoms due to insufficiently regulated blood sugar.
The chart below outlines the symptoms of type 1 and type 2 diabetes.
| Type 1 | Type 2 | |
|---|---|---|
| Symptoms | The following symptoms may develop over several weeks: • increased thirst and urination • increased hunger • blurry vision • tiredness and fatigue • numbness in hands and feet • sores that take a long time to heal • unexplained weight loss | The following symptoms may develop over several years: • increased thirst and urination • increased hunger • blurry vision • tiredness and fatigue • numbness in hands or feet • sores that take a long time to heal • unexplained weight loss |
Hyperglycemia
If a person’s blood sugar is too high, they may experience the signs and symptoms of hyperglycemia, including frequent urination and increased thirst.
This can lead to ketoacidosis, a potentially life threatening condition that needs urgent medical attention. It is more common in people with type 1 diabetes than in those with type 2.
Symptoms of ketoacidosis
Hypoglycemia
Hypoglycemia occurs when blood sugar levels are too low. Symptoms typically appear when a person’s blood sugar falls below 70 milligrams per deciliter (mg/dL).
Early symptoms include:
- sweating, chills, and a pale face
- a shaky, nervous, or anxious feeling
- fast heart rate
- dizziness and lightheadedness
- nausea
- weakness and tiredness
- headaches
- tingling
A person should consume a food or drink that is high in glucose to relieve the symptoms and prevent the problem from worsening. Ideally, they should follow that with protein-rich food.
Without treatment, a person may experience:
Hypoglycemia can be life threatening and needs immediate medical attention.
A person with diabetes should carry a medical ID so that others will know what to do if a problem occurs.
Type 1 diabetes often develops suddenly and is not preventable. It is often hereditary.
In contrast, type 2 diabetes may show no early symptoms, but routine blood tests can detect it.
People with obesity or risk factors for type 2 diabetes should regularly check their glucose levels to monitor for prediabetes or diabetes.
Healthcare professionals may use the following tests to diagnose diabetes:
- A1C test: This is a measurement of average blood glucose over 2 to 3 months.
- Fasting plasma glucose (FPG) test: This test measures glucose levels after 8+ hours of fasting.
- Oral glucose tolerance test (OGTT): This test assesses glucose processing before and after a person drinks a sugary solution.
- Random plasma glucose (RPG) test: This test can measure glucose at any time without fasting. Doctors use this test only when a person has symptoms of hyperglycemia or hyperglycemic crisis.
Depending on the results, the doctor may diagnose diabetes or prediabetes.
The following table shows which results
| A1C (%) | FPG (mg/dL) | OGTT (mg/dL after 2 hours) | RPG (mg/dL) | |
|---|---|---|---|---|
| Diabetes | 6.5% or more | 126 or more | 200 or more | 200 or more |
| Prediabetes | 5.7% to 6.4% | 100 to 125 | 140 to 199 | no value for prediabetes |
| Normal level | less than 5.7% | less than 100 | less than 140 | less than 200 |
People who may be more at risk of diabetes, such as those with a family history of the condition, should ask a doctor about regular screening.
People can check their blood glucose levels at home with meters that are available to buy online or in a pharmacy.
A person without known diabetes who has concerns about levels they have seen when using a home meter should visit their doctor for evaluation.
Without adequate treatment and management, both type 1 and type 2 diabetes can lead to long-term complications such as:
- cardiovascular disease, including a risk of heart attack and stroke
- kidney disease and kidney failure
- eye problems and vision loss
- nerve damage
- high blood pressure
- problems with wound healing
- ketoacidosis
Type 1 and type 2 have different causes, but they both involve insulin.
Insulin is a hormone that the pancreas produces to regulate the body’s use of blood sugar for energy.
Type 1 diabetes
The immune system destroys these cells, which means the body can no longer make enough insulin to regulate blood glucose levels. Once a person receives a diagnosis type 1 diabetes, they will need to use supplemental insulin for the rest of their life.
Healthcare professionals commonly diagnose type 1 in children and young adults, but it can happen later in life. It can start suddenly and tends to worsen quickly.
Type 2 diabetes
In type 2 diabetes, the body’s cells start to resist the effects of insulin. This means glucose cannot enter the cells. Instead, it builds up in the blood, and higher insulin levels are necessary to allow glucose to enter the cells. This is called insulin resistance.
Over time, the body stops producing enough insulin, so it can no longer use glucose effectively.
Symptoms may take years to appear. By using medications and maintaining appropriate diet and exercise habits from the early stages of the disease, a person may be able to delay the progression of the disease.
In the early stages, people with type 2 diabetes do not need supplemental insulin. However, as the disease progresses, they may need to use it to manage their blood glucose levels.
Genetic and environmental factors may trigger both type 1 and type 2 diabetes. However, many people may be able to avoid type 2 by maintaining healthy lifestyle habits.
Risk factors for type 1 diabetes
- family history of diabetes
- certain genetic features that affect the way the body produces or uses insulin
- possibly, exposure to some infections or viruses, such as mumps or rubella cytomegalovirus
Some medical conditions, such as cystic fibrosis and hemochromatosis, reduce the person’s insulin production and cause a type of diabetes very similar to type 1 diabetes.
Risk factors for type 2 diabetes include:
According to the National Institute of Diabetes and Digestive and Kidney Diseases, the following groups are also
- African Americans
- Hispanic people
- Native Americans
- Asian Americans
- Pacific Islanders
Vitamin D
Low levels of vitamin D may contribute to the development of type 2 diabetes by affecting insulin sensitivity and glucose metabolism.
The authors of a 2024 research review noted an association between low blood levels of vitamin D and the development of type 2 diabetes in older adults.
The primary source of vitamin D is exposure to sunlight. Certain foods, including oily fish and fortified dairy products, are
There is no cure for diabetes, but treatment can help people manage the condition and prevent it from worsening.
Gastric bypass surgery, lifestyle strategies, and medication can result in remission of type 2 diabetes.
| Type 1 | Type 2 | |
|---|---|---|
| Possible cure | • There is currently no cure, but people can manage symptoms with ongoing treatment. • Studies are assessing gene therapy, regenerative medicine using stem cells, and | • There is currently no cure, but some measures can slow progression and manage symptoms. • A gastric bypass may reduce symptoms in people with severe obesity. |
| Treatment with insulin and other drugs | • Daily insulin injections or an insulin pump can provide insulin as needed throughout the day and night. • Other drugs, such as pramlintide, can stop glucose levels from | • Metformin can reduce the amount of sugar the liver produces. • SGLT2 inhibitors, DPP-4 inhibitors, or alpha-glucosidase inhibitors can lower blood sugar levels. • Meglitinides or sulfonylureas can increase insulin levels. • Thiazolidinediones can increase sensitivity to insulin. • Glucagon-like peptide-1 agonists can increase insulin and reduce sugar levels. • Amylin analogs can reduce blood sugar by slowing digestion. • Insulin can help in some cases. |
| Lifestyle treatments | • Follow a treatment plan and medical advice. • Maintain an active lifestyle. • Pay attention to glucose levels when exercising. • Manage blood pressure and cholesterol levels. | • Follow a treatment plan and medical advice. • Maintain an active lifestyle. • Manage blood pressure and cholesterol levels. • Avoid smoking. • Know the signs of negative effects and complications. |
| Avoiding complications | • Follow a treatment plan. • Understand the signs of hypoglycemia and hyperglycemia. • Wear a medical ID. • Take precautions to avoid infections. • Have regular eye tests. • Check for wounds and seek treatment as soon as possible. | • Know the signs of possible complications. • Wear a medical ID. • Take precautions to avoid infections. • Check for wounds and seek treatment as soon as possible. • Have regular eye tests. • Follow a balanced diet and get regular exercise. |
| Prevention | It is not yet possible to prevent type 1 diabetes. | • Maintain a balanced diet. • Exercise regularly. • Avoid or quit smoking. • Follow a doctor’s instructions if they diagnose prediabetes. |
Breastfeeding
A 2019 research review suggests that breastfeeding an infant may help prevent them from developing type 2 diabetes later in life.
Other studies suggest that people who breastfeed an infant may benefit from a reduced risk of type 2 diabetes.
Diabetes is a serious health condition.
It is not currently possible to prevent type 1 diabetes, but insulin and other drugs can help people manage the symptoms.
While genetic factors may play a role in both types of diabetes, people may be able to reduce both the risk and the progression of type 2 diabetes by maintaining a healthy, active lifestyle.
Anyone with a diagnosis of prediabetes should also maintain healthy lifestyle habits, which can reduce or eliminate the risk of developing type 2 diabetes.
Type 1 diabetes is an autoimmune condition in which the immune system attacks the insulin-producing cells in the pancreas, leading to a sudden onset of symptoms such as frequent urination, extreme thirst, and weight loss.
It typically appears in childhood or adolescence and requires lifelong insulin therapy.
In contrast, type 2 diabetes is a metabolic disorder in which the body becomes resistant to insulin or does not produce enough of it.
It usually develops gradually in adults but is increasingly affecting children, often due to lifestyle factors.
People can manage type 2 diabetes through lifestyle strategies, medications, and sometimes the use of insulin.
If a person does not receive adequate treatment, both types of diabetes can cause serious complications.
