Type 2 diabetes is a long-term condition in which the body does not make enough of a hormone called insulin, or does not use it properly, so the level of sugar in the blood becomes too high [9].
This page provides general information. It does not replace advice from a doctor or another qualified healthcare professional.
Food is broken down into a sugar called glucose, which travels in the blood and gives the body energy. Insulin, a hormone made by an organ behind the stomach called the pancreas, acts like a key. It lets glucose move out of the blood and into cells [9,14].
In type 2 diabetes that system stops working well. Cells respond less to insulin, which doctors call insulin resistance, so the pancreas makes more to keep up. Over time it cannot meet the demand, and glucose builds up in the blood [14].
Type 1 diabetes is different. It is caused by the immune system attacking the insulin-making cells and always needs insulin [9,10]. Prediabetes is not diabetes: blood sugar is higher than usual but below the level needed for a diagnosis, and it raises the chance of type 2 later [10].
Older names for type 2 diabetes, such as adult-onset diabetes, are no longer accurate [7,11,14].
The International Diabetes Federation estimates that 589 million adults aged 20 to 79 were living with diabetes in 2024, about one in nine, rising to a projected 853 million by 2050 [1,2]. Type 2 diabetes is more than 90 percent of that total [1,8]. The World Health Organization, counting all ages, estimates 830 million in 2022 [8].
Many do not know they have it. The IDF estimates 252 million adults with diabetes, more than four in ten, are undiagnosed [1]. In the United States the Centers for Disease Control and Prevention counts 40.1 million people with diabetes in 2023, of whom 11.0 million are undiagnosed [4].
Numbers differ between regions. The IDF puts the Western Pacific at 215 million adults with diabetes, South-East Asia at 107 million, the Middle East and North Africa at 85 million, Europe at 66 million, North America and the Caribbean at 56 million, South and Central America at 35 million, and Africa at 25 million [2]. Three in four live in low-income and middle-income countries [1]. Africa has the lowest rate, 5.0 percent of adults, and the highest share undiagnosed, about 73 percent [3].
These are modeled estimates from surveys of differing quality. About 45 percent of countries in the IDF’s Africa region lack recent high-quality data [3].
There is no single cause. Type 2 diabetes develops from a mix of inherited factors and life circumstances, not all of them identified [14].
Genes are instructions inside our cells. Studies have found at least 150 small differences in DNA linked to type 2 diabetes, most of which appear in people with and without the condition, so it is the combination a person carries that shifts risk. There is no clear inheritance pattern, though many people who have it also have a parent, brother or sister with it [14].
Other factors include being 45 or older, carrying extra weight, low physical activity, having had gestational diabetes, non-alcoholic fatty liver disease, or prediabetes. Ancestry matters too: in the United States, risk is higher among African American, Hispanic or Latino, American Indian, Alaska Native, and some Pacific Islander and Asian American people [6]. The NHS advises that risk rises from age 40 in white people and from age 25 in people from South Asian, Chinese, Black African or Black Caribbean backgrounds [10].
Weight is one factor among several, not a moral question. Some people with type 2 diabetes have never carried extra weight, and many who do never develop it. Diabetes UK explains that people differ in how much fat the liver and pancreas can hold before blood sugar control suffers [15].
Many people have no symptoms for years, and those that appear build slowly, which is one reason the condition is often picked up on a routine blood test [5,8,10].
The most common symptoms are [10]:
Others include blurred vision, slow-healing cuts, and itching or repeated thrush around the genitals. Symptoms are the same in adults and children [10].
Over many years, high blood sugar damages blood vessels and nerves. This can lead to heart disease and stroke, eye damage including diabetic retinopathy, kidney problems, nerve damage, foot ulcers that sometimes lead to amputation, and gum disease. Regular check-ups find these changes early [8,12].
When to seek urgent help. Two rare situations need emergency care. Hyperosmolar hyperglycemic state and diabetic ketoacidosis both involve very high blood sugar and can be life threatening. Call your local emergency number if you have type 2 diabetes and are urinating a lot, feel very thirsty or sick, feel confused or very drowsy, or become short of breath [12].
Diagnosis is made with a blood test, usually arranged by a family doctor or nurse, with results within a few days [10].
Three tests are used [5]:
A random blood sugar of 200 mg/dL or above also indicates diabetes. A doctor usually repeats the test to confirm it, and may check for autoantibodies or ketones to rule out type 1 [5].
Diagnosis is often delayed. Since early type 2 diabetes frequently causes no symptoms, it is sometimes found only once complications have begun [8]. This is why testing is offered to people at higher risk who feel well [5,10].
There is no cure, though the condition can be managed well and some people reach remission.
Daily habits. The NHS advises a diet built around vegetables, fruit, wholegrain foods and pulses, at least two and a half hours of activity across the week, stopping smoking, and limiting alcohol. Very low-calorie diets should only be started with medical advice. Everyone should be offered a structured education course within a year of diagnosis [11].
Medicines. Guidance differs between countries, so local practice may not match what is described elsewhere. In England, NICE recommends metformin first, often alongside an SGLT2 inhibitor, which lets extra sugar leave the body in urine [11,13]. A GLP-1 receptor agonist, usually a weekly injection, may be added for people with heart disease or where other treatments have not worked. Insulin is used when other medicines are not enough [11]. Tirzepatide, sold as Mounjaro, acts on the GIP and GLP-1 receptors and was approved by the United States Food and Drug Administration in May 2022 for adults with type 2 diabetes [17]. The American Diabetes Association updates its Standards of Care yearly [16].
Surgery. Weight-loss surgery, also called metabolic or bariatric surgery, can improve blood sugar substantially. Trials have found it more effective than medicines and lifestyle change alone at holding blood sugar in range without medication for up to five years [19].
Remission. Remission means an HbA1c below 6.5 percent, held for at least three months, without glucose-lowering medicine. Diabetes UK explains that the strongest evidence points to weight loss, that chances improve the sooner it is tried after diagnosis, and that losing around 15 kg helps many people living with overweight or obesity. It is not a cure, and it is not achievable for everyone [15].
Monitoring. Expect an HbA1c test every three to six months, a foot check and eye screening every one to two years, and yearly checks of weight, cholesterol, blood pressure and kidney health [11].
Most people manage the condition alongside ordinary life. Care is usually led by a family doctor and a diabetes nurse, with specialists involved when needed [10,11].
Carrying medical identification is worth considering, and medicines belong in hand luggage when you travel. If you take insulin or have low blood sugar episodes, driving rules may apply. Some medicines are paused during vomiting, diarrhea or fever, on medical advice [11].
Pregnancy needs planning. Anyone thinking about having a baby should ask early for a pre-conception clinic or diabetes team referral, since some medicines need changing to ones that are safe in pregnancy [11].
A diagnosis can also feel overwhelming, and the daily work of monitoring, appointments and medicines adds up. Diabetes teams expect these conversations, and support organizations are listed below [10].
Clinical trials are research studies that test whether a treatment works and is safe. Type 2 diabetes is an active research area, so studies come up often. Deciding whether to look into one is a personal choice.
Be clear on what a study involves:
Every trial has rules about who can take part. These are called eligibility criteria. Some describe who can join, others who cannot. For a type 2 diabetes study they might include a confirmed diagnosis, an HbA1c within a stated range, an age range, which diabetes medicines a person already takes, body weight, kidney function, or a history of heart disease, pancreatitis or weight-loss surgery.
trialport’s medifit helps people consider information related to possible medical suitability. It does not diagnose a condition, confirm eligibility or replace formal screening by the study team.
Explore type 2 diabetes clinical trials through trialport
Medical suitability is only part of the picture. A study can suit on paper and still be difficult in practice. Worth thinking through:
trialport’s readifit helps people reflect on their understanding, motivation, time, routines, support, emotions and practical arrangements.
Useful questions to put to a research team:
Taking part is voluntary. A person can ask questions, speak with people they trust and choose not to participate.
Search for clinical trials at app.trialport.com.
Current work includes:
Study status checked: 3 August 2026. Recruitment status changes often, so check app.trialport.com for current information.
In the United Kingdom, Diabetes UK offers a helpline, guidance on remission, local groups and a risk-check tool [15]. The NHS type 2 diabetes pages cover symptoms, treatment and complications, and list free education courses [10,11,12].
In the United States, the Centers for Disease Control and Prevention publishes plain-language pages on testing, risk and prevention [4,5,6], and the American Diabetes Association provides education alongside the Standards of Care [16]. In Australia, Diabetes Australia provides national information and support [20].
Elsewhere, the International Diabetes Federation is an umbrella body for more than 250 national diabetes associations across 158 countries [1].
The actor Tom Hanks has spoken publicly about living with type 2 diabetes, describing on television how his doctor gave him the diagnosis after years of raised blood sugar [21].
Public assumptions about someone’s diagnosis are often wrong. This page names only people who have described the condition themselves in public.
Can type 2 diabetes be reversed?
Doctors say remission rather than reversal. It means an HbA1c below 6.5 percent for at least three months without glucose-lowering medicine, is most often reached through weight loss, and is more likely the sooner it is tried after diagnosis. Blood sugar can rise again, so check-ups continue [15].
Is type 2 diabetes inherited?
Not in a simple way. There is no clear inheritance pattern, though having a parent, brother or sister with it raises your chance, through both shared genes and shared habits [14].
Can children get type 2 diabetes?
Yes, and increasingly. In the United States, new cases in people under 20 rose from 9 per 100,000 a year in 2002 to 18 per 100,000 in 2018, with diagnosis usually around age 16 [7].
What is prediabetes?
Blood sugar above the usual range but below the level needed to diagnose diabetes. Most people have no symptoms. It raises the chance of type 2 diabetes later, and changes to food and activity can prevent or delay that [8,10].
Is it caused by eating too much sugar?
No single food causes it. It develops from a combination of inherited factors, weight, activity, age and other health conditions [14].
Written by: trialport editorial team
Reviewed by: Keith Berelowitz, Founder and CEO, trialport
Reviewed on: 3 August 2026
Next review due: 3 August 2027
References last checked: 3 August 2026