Diabetes is a lifelong condition that causes a person's blood sugar level to become too high. There are 2 main types of diabetes: Type 2 diabetes is far more common than type 1. In the UK, around 90% of all adults with diabetes have type 2. During pregnancy, some women have such high levels of blood glucose that their body is unable to produce enough
insulin to absorb it all. This is known as gestational diabetes. Many more people have blood sugar levels above the normal range, but not high enough to be diagnosed as having diabetes. This is sometimes known as pre-diabetes. If your blood sugar level is above the normal range, your
risk of developing full-blown diabetes is increased. It's very important for diabetes to be diagnosed as early as possible because it will get progressively worse if left untreated. Visit your GP as soon as possible if you experience the main symptoms of diabetes, which include: Type 1 diabetes can develop quickly over weeks or even days. Many people have type 2 diabetes for years without realising because the early symptoms tend to be general. The amount of sugar in the blood is controlled by a hormone called insulin, which is produced by the
pancreas (a gland behind the stomach). When food is digested and enters your bloodstream, insulin moves glucose out of the blood and into cells, where it's broken down to produce energy. However, if you have diabetes, your body is unable to break down glucose into energy. This is because there's either not enough insulin to move the glucose, or the insulin produced does not work properly. There
are no lifestyle changes you can make to lower your risk of type 1 diabetes. You can help manage type 2 diabetes through healthy eating, regular exercise and achieving a healthy body weight. Read about how to reduce your diabetes risk. If you're diagnosed with
diabetes, you'll need to eat healthily, take regular exercise and carry out regular blood tests to ensure your blood glucose levels stay balanced. You can use the BMI healthy weight calculator to check whether you're a
healthy weight. People diagnosed with type 1 diabetes also require regular insulin injections for the rest of their life. As type 2 diabetes is a progressive condition, medicine may eventually be required, usually in the form of tablets. Read about: Everyone with diabetes aged 12 or over should be invited to have their eyes screened once a year. If you have diabetes, your eyes are at risk from diabetic retinopathy, a condition that
can lead to sight loss if it's not treated. Screening, which involves a 30-minute check to examine the back of the eyes, is a way of detecting the condition early so it can be treated more effectively.Pre-diabetes
When to see a doctor
Causes of diabetes
Living with diabetes
Diabetic eye screening
Read more about diabetic eye screening.
Page last reviewed: 11 July 2019
Next review due: 11 July 2022
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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.
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.
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:
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:
- 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 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.
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.