Type 2 Diabetes
A common condition of high blood sugar from insulin resistance
Quick Facts
- Type: Metabolic / endocrine condition
- Cause: Insulin resistance and reduced insulin output
- Often: Develops slowly, sometimes silently
- Management: Lifestyle, medication, sometimes insulin
Overview
Type 2 diabetes is a long-term condition in which blood sugar (glucose) stays too high because the body does not use insulin effectively. Insulin is the hormone that helps sugar move from the blood into cells for energy. In type 2 diabetes, cells become resistant to insulin and, over time, the pancreas cannot keep up with the extra demand.
It is the most common form of diabetes and is strongly linked to factors such as excess weight, inactivity, genetics, and age, though it can affect anyone. Type 2 diabetes often develops gradually and may go unnoticed for years. The good news is that it can frequently be managed, and sometimes improved substantially, with lifestyle changes and treatment, reducing the risk of serious complications.
Symptoms
Symptoms develop slowly and may be mild or absent at first. They can include:
- Increased thirst and frequent urination
- Increased hunger
- Fatigue
- Blurred vision
- Slow-healing sores or frequent infections
- Numbness or tingling in the hands or feet
- Areas of darkened skin, often in the neck folds or armpits
Because symptoms can be subtle, many people are diagnosed through routine blood tests. Very high blood sugar can occasionally cause a serious emergency with extreme dehydration and confusion, which requires immediate care.
Causes
Type 2 diabetes develops from a combination of insulin resistance and the pancreas not producing enough insulin to compensate. Contributing factors include:
- Insulin resistance: Cells, especially in muscle, fat, and the liver, respond poorly to insulin.
- Genetics and family history: A strong influence on risk.
- Excess weight, particularly around the abdomen.
- Physical inactivity.
- Age: Risk rises with age, though it increasingly affects younger people.
Risk Factors
- Overweight or obesity
- Family history of type 2 diabetes
- Physical inactivity
- Older age
- Prediabetes (blood sugar higher than normal but not yet diabetic)
- History of gestational diabetes or polycystic ovary syndrome
- High blood pressure or abnormal cholesterol
- Certain ethnic backgrounds with higher risk
Diagnosis
Type 2 diabetes is diagnosed with blood tests that measure blood sugar:
- A1C test: Reflects average blood sugar over the past 2 to 3 months.
- Fasting plasma glucose: Blood sugar after not eating overnight.
- Oral glucose tolerance test: Blood sugar before and after a sugary drink.
- Random blood glucose: A high value with symptoms can support the diagnosis.
Screening is recommended for people with risk factors, since early detection allows earlier treatment. The same tests identify prediabetes.
Treatment
Treatment aims to keep blood sugar in a healthy range and reduce complications. It is tailored to the individual and often combines:
- Lifestyle changes: A balanced diet, regular physical activity, and weight loss when needed. These are the foundation and can be very effective.
- Blood sugar monitoring as advised.
- Medications: Several types of oral and injectable medicines lower blood sugar in different ways; metformin is commonly used first.
- Insulin: Some people eventually need insulin to maintain control.
- Managing related risks: Blood pressure, cholesterol, and not smoking, to protect the heart and blood vessels.
With sustained lifestyle change and weight loss, some people achieve normal blood sugar without medication, though ongoing follow-up remains important.
Prevention
- Maintain a healthy weight, or lose a modest amount of weight if overweight
- Be physically active most days of the week
- Eat a diet rich in vegetables, fruits, whole grains, and fiber, and limit sugary drinks
- Avoid tobacco
- Get screened if you have prediabetes or other risk factors, as treating prediabetes can prevent or delay diabetes
When to See a Doctor
See a doctor if you have symptoms such as increased thirst, frequent urination, unexplained fatigue, or blurred vision, or if you have risk factors and have not been screened. Seek urgent care for:
- Very high blood sugar with extreme thirst, confusion, or drowsiness
- Signs of severe dehydration
- Symptoms of low blood sugar (shakiness, sweating, confusion) if you take glucose-lowering medicine
Frequently Asked Questions
Can type 2 diabetes be reversed?
Type 2 diabetes can sometimes be improved enough that blood sugar returns to a normal range, often through significant weight loss, diet change, and exercise. This is sometimes called remission, but it is not a permanent cure, and ongoing healthy habits and monitoring are still needed.
What is the difference between type 1 and type 2 diabetes?
Type 2 diabetes mainly involves the body resisting insulin and is linked to weight, activity, and genetics. Type 1 is an autoimmune disease in which the pancreas stops making insulin. Type 1 always requires insulin, while type 2 is often managed with lifestyle and oral medicines first.
How is type 2 diabetes diagnosed?
It is diagnosed with blood tests such as the A1C, fasting blood glucose, or an oral glucose tolerance test. Screening is recommended for people with risk factors because the condition can develop silently for years.
Will I need insulin for type 2 diabetes?
Not necessarily. Many people manage type 2 diabetes with lifestyle changes and oral or other non-insulin medicines. Over time, some people do need insulin to keep blood sugar controlled, which is a normal part of managing the condition, not a personal failure.
How can I lower my risk of type 2 diabetes?
Maintaining a healthy weight, staying physically active, eating a balanced diet with limited sugary drinks, and not smoking all lower risk. If you have prediabetes, these steps can prevent or delay the progression to type 2 diabetes.
References
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Type 2 diabetes.
- American Diabetes Association.
- Centers for Disease Control and Prevention (CDC). Diabetes.
- MedlinePlus, U.S. National Library of Medicine. Type 2 diabetes.