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Type 1 and type 2 diabetes both occur when the body cannot properly store and use glucose, which is essential for energy. This glucose then collects in the blood and does not reach the cells that need it, leading to serious complications.

Type 1 diabetes usually appears first in children and adolescents, but it can also occur in adults. In type 1 diabetes the immune system attacks pancreatic beta cells so that they can no longer produce insulin.

There is no way to prevent type 1 diabetes and it is often hereditary. Around 5-10% of people with diabetes have type 1.

Type 2 diabetes is more likely to appear as people age, but children may still develop it. In this type, the pancreas produces insulin, but the body cannot use it effectively. Lifestyle factors appear to play a role in its development. The majority of people with diabetes have type 2 diabetes.

Both types of diabetes can lead to complications such as cardiovascular disease, kidney disease, vision loss, neurological conditions, and damage to blood vessels and organs.

The CDC estimates that more than 34 million people in the United States may have diabetes, and almost 25% of them may not know they have it.

This article will look at the similarities and differences between type 1 and type 2 diabetes.

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A person with diabetes may experience adverse symptoms due to poorly-regulated blood sugar.

Other aspects of metabolic syndrome also occur alongside type 2 diabetes, including obesity, high blood pressure, and cardiovascular disease.

The chart below outlines the symptoms of type 1 and type 2 diabetes.

Type 1Type 2
SymptomsAppearance over several weeks of:
– 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
Development over several years of:
– 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.

Symptoms of ketoacidosis include:

  • difficulty breathing
  • a fruity smell on the breath
  • nausea and vomiting
  • a dry mouth
  • coma

Learn more about hyperglycemia here.

Hypoglycemia

Hypoglycemia is when blood sugar levels are too low. Symptoms typically appear when blood sugar levels fall below 70 milligrams per deciliter (mg/dL).

Early symptoms include:

  • sweating, chills, and a pale face
  • feeling shaky, nervous, and anxious
  • rapid heartbeat
  • feeling dizzy and lightheaded
  • nausea
  • feeling weak and tired
  • headaches
  • tingling

A person should consume a high-glucose food or drink to relieve the symptoms and prevent the problem from getting worse. Ideally, a person should follow this with protein-rich food.

Without treatment, the person may experience:

  • seizures
  • loss of consciousness
  • coma

This condition 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.

Find out more about hypoglycemia here.

The onset of type 1 diabetes tends to be sudden. If a person has symptoms, the person should see a doctor as soon as possible.

By contrast, a person in the early stages of type 2 diabetes may show no symptoms. However, a routine blood test at this stage will show elevated blood sugar levels.

People with obesity and other risk factors for type 2 diabetes should have regular checks to ensure their glucose levels are healthy. If tests show they are high, they may have diabetes or prediabetes.

Learn more about prediabetes here.

Prediabetes is where a person has elevated blood glucose levels but does not yet meet the levels necessary for a type 2 diabetes diagnosis.

The following tests can help diagnose type 1 or type 2 diabetes, but they may not all be useful for both types:

  • A1C test: For an A1C test, a doctor will take a blood sample that gives the doctor an indication of a person’s average blood glucose level over the past 2-3 months.
  • Fasting plasma glucose (FPG) test: This measures a person’s blood glucose levels after a period of fasting. Patients must not eat for at least 8 hours before the test, and as a result, many take the test before breakfast.
  • Oral glucose tolerance test (OGTT): This test measures how a person processes glucose. A patient will take a blood glucose test 2 hours before and 2 hours after drinking a sugary drink.
  • Random plasma glucose (RPG) test: A doctor will use an RPG test to measure a person’s blood glucose level at any point in a day. A patient does not have to fast before taking this test.

Depending on the results, the doctor may diagnose diabetes or prediabetes.

The following table shows which results indicate diabetes:

A1C (%) FPG
(mg/dl)
OGTT
(mg/dl after 2 hours)
RPG
(mg/dl)
Diabetes6.5% or above126 or over200 or over200 or over
Prediabetes5.7–6.4%100–125140–199
Normalbelow 5.7%below 100below 140below 200

The ADA recommends regular screening for type 2 diabetes in people aged 45 years and above. Younger people who may be more at risk of diabetes, such as those with a family history of the condition, should also regularly screen for type 2 diabetes.

People can check their own blood glucose levels at home. A person without known diabetes who has concerns about values taken with a home meter should visit their doctor for evaluation.

Testing kits are available for purchase online.

Both type 1 and type 2 diabetes can lead to long-term complications if a person does not adequately manage them. These complications can include:

Type 1 and type 2 have different causes, but they both involve insulin.

Insulin is a type of hormone. The pancreas produces it to regulate the way blood sugar becomes energy.

Type 1 diabetes

In this type, scientists believe that the immune system mistakenly attacks the pancreatic beta cells, which produce insulin. They do not know what causes this to happen, but childhood infections may play a role.

The immune system destroys these cells, which means that the body can no longer make enough insulin to regulate blood glucose levels. A person with type 1 diabetes will need to use supplemental insulin from when they receive the diagnosis through the rest of their life.

Type 1 often is first diagnosed when people are children and young adults, but it can happen later in life. It can start suddenly, and it 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 levels of insulin are required to allow it to enter the cells. This is called insulin resistance.

In time, the body stops producing enough insulin, so it can no longer use glucose effectively.

Symptoms may take years to appear. People may use medications, diet, and exercise from the early stages to mitigate the progression of the disease.

In the early stages, a person with type 2 diabetes does not need supplemental insulin. As the disease progresses, however, they may need 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 making healthy lifestyle choices.

Risk factors for type 1 diabetes include:

  • having a family history of diabetes
  • being born with 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 or 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:

  • having a family member with type 2 diabetes
  • having obesity
  • smoking
  • following an unhealthy diet
  • a lack of exercise
  • the use of some medications, including some medications for HIV and chronic steroids

People from certain ethnic groups are more likely to develop type 2 diabetes. These include Black and Hispanic people, Native Americans and Native Alaskans, Pacific Islanders, and some people of Asian origin.

Vitamin D

Low levels of vitamin D may play a role in the development of both type 1 and type 2 diabetes.

A review published in 2017 suggests that when a person lacks vitamin D, certain processes in the body, such as immune function and insulin sensitivity, do not work as well as they should. According to the review’s authors, this may increase a person’s risk of diabetes.

The primary source of vitamin D is exposure to sunlight. Food sources including oily fish and fortified dairy products are also high in vitamin D.

There is no cure for diabetes, but treatment can help people manage the condition and prevent it from worsening. Here are some points about treating and managing diabetes.

Gastric bypass surgery, lifestyle changes, and medication can result in remission of type 2 diabetes.

Type 1Type 2
Possible cure– There is currently no cure, but lifetime treatment can manage symptoms.
– Studies are assessing gene therapy, regenerative medicine using stem cells, or pancreatic islet transplantation as potential treatment options.
– There is currently no cure, but 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 using an insulin pump can provide insulin as needed through the day and night.
– Other drugs, such as pramlintide, can stop glucose levels from rising too far.
– Metformin can reduce the amount of sugar the liver produces.
– SGLT2 inhibitors, DPP-4 inhibitors, or alpha-glucosidase inhibitors can reduce 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
– follow an active, healthful lifestyle
– pay attention to glucose levels when exercising
– manage blood pressure and high cholesterol levels
– follow a treatment plan and medical advice.
– follow an active, healthful lifestyle
– manage blood pressure and high cholesterol levels
– avoid smoking
– know the signs of adverse effects and complications
Avoiding complications– follow the treatment plan
– understand the signs of hypoglycemia and hyperglycemia
– wear a medical ID.
– take measures to avoid infections
– have regular eye tests
– check for wounds and seek early treatment
– know the signs of possible complications
– wear a medical ID
– take measures to avoid infections
– check for wounds and seek early treatment
– have regular eye tests
– follow a healthy diet and get regular exercise
Prevention– It is not yet possible to prevent type 1 diabetes.– Follow a healthy diet with regular exercise, avoid or quit smoking, and follow a doctor’s instructions if they diagnose prediabetes.

Find out more about non-insulin drugs for type 2 diabetes here.

Breastfeeding

Reviews suggest that breastfeeding or chestfeeding infants may help prevent them from developing type 2 diabetes later in life. Other studies suggest that a person who breastfeeds or chestfeeds an infant may benefit from a reduced risk of type 2 diabetes.

Diabetes is a serious condition.

It is not currently possible for a person to prevent type 1 diabetes, but insulin and other drugs can help manage symptoms.

While there may be a hereditary link for both types of diabetes, people can both reduce the risk and manage the progress of type 2 diabetes by following a healthy, active lifestyle.

Anyone with a diagnosis of prediabetes should also make healthy lifestyle choices, as this can reduce or eliminate the risk of type 2 diabetes developing.