Type 2 Diabetes
Type 2 diabetes is a common long-term condition in which the body cannot use insulin properly or does not make enough, so blood sugar levels rise. Over time, high blood sugar can damage the eyes, kidneys, nerves and heart. This is a brief overview — for detailed clinical information, see our Endocrine & Metabolic condition pages.
Overview
What is type 2 diabetes?
Type 2 diabetes is a long-term condition in which the level of sugar (glucose) in the blood is too high. It develops because the body becomes resistant to the hormone insulin and gradually does not make enough of it. It is by far the most common form of diabetes.
How is it different from type 1 diabetes?
In type 1 diabetes the immune system destroys the cells that make insulin, so insulin treatment is essential, usually from a young age. Type 2 diabetes is driven mainly by insulin resistance, is strongly linked to weight, activity and genetics, and can often be managed with lifestyle changes and tablets, though some people also need insulin over time.
Symptoms and Causes
What are the symptoms?
Symptoms often develop slowly and can be easy to miss. They may include increased thirst, passing urine more often (especially at night), tiredness, blurred vision and wounds that heal slowly. Many people have no obvious symptoms and are diagnosed through a routine blood test.
What causes it and who is at risk?
The key problem is insulin resistance. Risk is higher with being overweight, physical inactivity, increasing age, a family history of diabetes, certain ethnic backgrounds, and a history of diabetes during pregnancy (gestational diabetes).
Diagnosis and Tests
How is type 2 diabetes diagnosed?
It is diagnosed with blood tests that measure your blood sugar — most commonly the HbA1c test, which reflects your average glucose over the past two to three months, along with fasting glucose or an oral glucose tolerance test. Your doctor interprets the results in the context of your symptoms and risk factors.
Management and Treatment
How is type 2 diabetes managed?
Management combines healthy eating, regular activity and weight loss with regular monitoring of blood sugar. Many people take medicines such as metformin, and some eventually need insulin. Just as important is managing blood pressure and cholesterol and screening for complications affecting the eyes, kidneys, nerves and heart.
Prevention
Can type 2 diabetes be prevented or reversed?
In many cases its onset can be prevented or delayed by maintaining a healthy weight, eating well and staying active. There is also growing evidence that some people can achieve remission — blood sugar back in the normal range without medication — through substantial, sustained weight loss. Discuss what is realistic for you with your doctor.
Additional Common Questions
What is the difference between type 1 and type 2 diabetes?
In type 1 diabetes the body makes little or no insulin because the immune system has destroyed the insulin-producing cells, so insulin treatment is always needed. In type 2 diabetes the body cannot use insulin properly or make enough; it is more common and strongly linked to lifestyle and genetic factors.
Can type 2 diabetes be prevented or improved?
Often a great deal can be done. Maintaining a healthy weight, eating well, staying active and not smoking can lower the risk of developing type 2 diabetes and help control it once present. Speak with a doctor about your individual risk and management.
Where can I find detailed information on treatment?
This article is a brief overview only. For in-depth clinical information on diagnosing and managing type 2 diabetes, please see our Endocrine & Metabolic conditions pages, and discuss your situation with a qualified clinician.
Sources
This health topic is for general information and is not a substitute for professional medical advice. Always consult a qualified clinician about your individual situation. See our medical disclaimer.