Type 2 diabetes has problems with the way the body regulates and uses sugar (glucose) for fuel. This long-term (chronic) condition results in too much sugar circulating into the bloodstream. Ultimately, high blood sugar levels can lead to disorders of the circulatory, nervous, and immune systems.
Two interrelated problems play a major role in Type 2 diabetes. The pancreas does not produce enough insulin (the hormone that regulates the movement of sugar into cells), and the cells do not respond well to insulin and consume less sugar.
Type 2 diabetes was formerly called adult diabetes, but both type 1 diabetes and type 2 diabetes can begin in childhood and adulthood. Although type 2 is more common among older people, the increase in obese children has led to an increase in Type 2 diabetes in young adults.
Type 2 diabetes cannot be cured, but losing weight, eating right, and exercising can help manage the disease. Diabetes medications or insulin therapy may be necessary if diet and exercise are not sufficient to control blood sugar.
The signs and symptoms of Type 2 diabetes often progress slowly. You can live with type 2 diabetes for years without knowing it. When signs and symptoms appear, they may include:
- Increased thirst
- Frequent urination
- Increased hunger
- Unintentional weight loss
- Blurred vision
- Inflammation heals slowly
- Frequent infections
- Numbness in arms or legs44 Dark skin, usually in the armpits and neck
Type 2 diabetes is primarily the result of two interrelated problems. The cells of the muscle, adipose tissue, and liver become resistant to insulin. Because these cells don't interact normally with insulin, they don't get enough sugar.
: The pancreas cannot produce enough insulin to control blood sugar levels.
Exactly why this happens is not known, but overweight and sedentary lifestyles are the main factors.
How Insulin Works
Insulin is a hormone produced by the glands behind and below the stomach (pancreas). Insulin regulates the body's use of sugar in the following ways:
Sugar in the bloodstream causes the pancreas to secrete Insulin .
Insulin circulates in the bloodstream, allowing sugar to enter the cells.
The amount of sugar in the blood decreases.
In response to this decrease, the pancreas secretes less insulin.
The Role of Glucose
Glucose (sugar) is the main energy source for the cells that make up muscles and other tissues. Use and control of glucose levels include:
Glucose comes from two main sources: food and the liver.
Glucose is absorbed into the blood and enters the cells with the help of insulin.
The liver stores and produces glucose.
When Glucose levels are low, such as after not eating for a while, the liver breaks down stored glycogen into glucose to keep glucose levels within the normal range.
This process does not work well in type 2 diabetes
Instead of entering cells, blood sugar accumulates in the bloodstream. When blood sugar rises, the insulin-producing pancreatic beta cells secrete more insulin. Eventually, these cells become damaged and cannot produce enough insulin to meet the body's needs.
In less common type 1 diabetes, the immune system inadvertently destroys beta cells, leaving little or no insulin in the body.
Factors that may increase your risk of developing type 2 diabetes include:
Being overweight or obese is the main risk.
Fat distribution. Storing fat primarily in the abdomen rather than the hips and thighs represents a greater risk. Men with a waist circumference of 40 inches (101.6 centimeters) or more or women with a waist circumference of 35 inches (88.9 centimeters) or more are at an increased risk of type 2 diabetes.
The less active you are, the greater your risk. Physical activity helps control weight, uses glucose for energy, and makes cells more sensitive to insulin.
If a parent or sibling has type 2 diabetes, the risk of type 2 diabetes is increased.
Race and Ethnicity. It is not clear why people of certain races and ethnicities, including blacks, Hispanics, Native Americans and Asians, and Pacific Islanders, are more likely to develop type 2 diabetes than whites.
Lipid levels in the blood.
The increased risk is associated with low levels of high-density lipoprotein (HDL) cholesterol ("good" cholesterol) and high triglyceride levels.
epoch. The risk of type 2 diabetes increases with age, especially after age 45.
Prediabetes. Prediabetes is a condition in which blood sugar levels are higher than normal but not high enough to be classified as diabetes. If left untreated, prediabetes often progresses to type 2 diabetes.
If you develop gestational diabetes during pregnancy or if you have a baby weighing more than 4 kg (9 pounds), your risk of developing type 2 diabetes is increased.
Polycystic Ovary Syndrome. Having polycystic ovary syndrome, a common condition characterized by irregular menstrual cycles, excessive hair growth, and obesity, increases your risk of developing diabetes.
Dark-skinned areas, usually in the armpits and neck. This condition often indicates insulin resistance.
Type 2 diabetes affects many major organs, including the heart, blood vessels, nerves, eyes, and kidneys. Factors that increase your risk of diabetes are also risk factors for other serious chronic diseases. Controlling diabetes and controlling blood sugar can reduce the risk of these complications or co-morbidities (comorbidities).
Potential complications of diabetes and common comorbidities include:
Heart and Vascular Diseases.
Diabetes is associated with an increased risk of heart disease, stroke, high blood pressure, and narrowing of blood vessels (atherosclerosis).
Nerve damage in extremities (neuropathy).
High blood sugar can damage or destroy nerves over time, causing tingling, numbness, burning, pain, or loss of sensation, usually starting in the toes or fingertips and gradually spreading upwards.
Other nerve damage.
Damage to the cardiac nerves can contribute to abnormal heart rhythms. Nerve damage in the digestive system can cause nausea, vomiting, diarrhea, or constipation. In men, nerve damage can cause erectile dysfunction.
Diabetes can lead to chronic kidney disease that requires dialysis or a kidney transplant, or irreversible end-stage kidney disease.
Diabetes increases the risk of serious eye conditions such as cataracts and glaucoma and can damage blood vessels in the retina, leading to blindness.
Diabetes can make you more susceptible to skin problems, including bacterial and fungal infections.
If left untreated, cuts and blisters can become serious infections that may not heal well. Serious injuries may require amputation of the toe, foot, or lower leg.
Hearing problems are more common in people with diabetes.
Obstructive sleep apnea is common in people with type 2 diabetes. Obesity may be a major contributing factor to both conditions. It is unclear whether treatment for sleep apnea improves blood sugar control.
Type 2 diabetes appears to increase the risk of Alzheimer's disease and other disorders that cause dementia. Poor blood sugar control results in faster declines in memory and other thinking skills.
Choosing a healthy lifestyle can prevent type 2 diabetes, even if you have a biological relative with diabetes.
If you have been diagnosed with pre-diabetes, lifestyle changes can slow or stop the progression of diabetes.
A healthy lifestyle includes:
Eat healthy food.
Choose foods that are low in fat and calories and high in fiber. Focus on fruits, vegetables, and whole grains.
Aim for at least 150 minutes per week of moderate to vigorous aerobic activity, such as brisk walking, biking, running, or swimming.
Losing and maintaining some weight can delay the progression from prediabetes to type 2 diabetes. If you have prediabetes, losing 7-10% of your body weight can reduce your risk of developing diabetes.
Do not remain idle for long periods. Sitting still for long periods may increase your risk of developing type 2 diabetes. Get up every 30 minutes and try to move for at least a few minutes.
People with prediabetes may be given metformin, an oral medication for diabetes (such as Fortamet and Glumecha), to reduce the risk of type 2 diabetes. It is usually given to older people who are obese and cannot lower their blood sugar through lifestyle changes.
Medication may be needed if lifestyle changes do not meet blood sugar goals. Some of the most common types of type 2 diabetes are:
Metformin (Fortamet, Glucophage, Glumetza, Riomet). It is usually the first drug used to treat type 2 diabetes. It lowers the amount of glucose produced by the liver and helps the body respond better to the insulin it produces.
Sulfonylurea. This group of drugs helps the body produce more insulin. These include glimepiride (Amaryl), glipizide (Glucotrol, Metaglip) and glyburide (diabetes, Micronase).
Meglitinide. They help the body produce more insulin and act faster than sulfonylurea derivatives. You may take nateglinide (Starix) or repaglinide (Prandin).
Thiazolidinedione. Like metformin, it increases insulin sensitivity. You can get pioglitazone (Actos) or rosiglitazone (Avandia). However, they also increase the risk of heart problems, so they are usually not the first choice for treatment.
Drugs such as linagliptin (Trajenta), saxagliptin (Ongliza), and sitagliptin (Januvia) help lower blood sugar, but can also cause joint pain and inflammation of the pancreas.
GLP-1 receptor agonist. These drugs are taken with a needle to slow digestion and lower blood sugar. Some of the most common are exenatide (Byetta, Bydureon), liraglutide (Victoza), and semaglutide (Ozempic).
SGLT2 inhibitor. It helps the kidneys filter out more glucose. You can get canagliflozin (Invokana), dapagliflozin (Farxiga), or empagliflozin (Jardiance). Empagliflozin has also been shown to be effective in reducing the risk of hospitalization or death from heart failure.
GIP and GLP-1 receptor agonists. Tirzepatide (Mounjaro) is the first in its class and improves glycemic control by activating both GLP-1 and GIP receptors.
Insulin. Long-term injections, such as insulin detemir (Lebemir) or insulin glargine (Lantus), can be taken at night.
Even making lifestyle changes and taking medications as directed, blood sugar levels can worsen over time. It doesn't mean you did something wrong. Diabetes progresses and many people eventually need more than one drug.
Taking two or more drugs to control type 2 diabetes is called combination therapy.
You and your doctor should work together to find the formula that works best for you. Typically, you continue to take metformin and add something else.
Depends on the situation. For example, some drugs control the spike in blood sugar that occurs right after a meal (which your doctor may call hyperglycemia). Others are more effective at stopping the drop in blood sugar (hypoglycemia) between meals. Some may help reduce weight or cholesterol, as well as diabetes.
You and your doctor should discuss any possible side effects. Cost can also be an issue.
If you are taking a drug for any other purpose, this should be taken into account in all decisions.
If you start taking a new combination of drugs, you should see your doctor more often.
Adding a second drug may not control blood sugar. Or, a combination of the two drugs may only work for a short time. If this happens, your doctor may consider a third non-insulin drug or start insulin therapy.
Prevention of Type 2 Diabetes
A Healthy Lifestyle Helps Reduce Your Risk of Developing Diabetes
To go on a diet. Losing just 7 to 10 percent of your body weight can cut your risk of developing type 2 diabetes in half.
Activate. A brisk walk for 30 minutes a day can cut your risk by almost a third.
Eat right. Avoid highly processed carbohydrates, sugary drinks, trans fats, and saturated fats. Limit your intake of red and processed meats.
Quit smoking. To avoid weight gain after quitting, talk to your doctor so that you don't create one problem while you work on the other.
Complications of Type 2 Diabetes
Over time, high blood sugar can damage and cause problems such as:
Heart and blood vessels. Five times more likely to have heart disease or stroke. There is also an increased risk of clogged blood vessels (atherosclerosis) and chest pain (angina).
Kidneys. Dialysis or kidney replacement may be needed if the kidneys are damaged or have kidney failure.
High blood sugar can damage small blood vessels at the back of the eye (retinopathy). If left untreated, it can lead to blindness.
This can cause problems with digestion, leg sensation, and sexual response.
Leather. In addition, poor blood circulation can cause wounds to heal more slowly and become infected.
Women with diabetes are more likely to have miscarriages, stillbirths, or children with birth defects.
Sleep apnea, a condition in which breathing stops and begins during sleep, may develop.
Hearing. You likely have a hearing problem, but it is not clear why.
High blood sugar can damage your brain and increase your risk of developing Alzheimer's.
People with the disease are twice as likely to get depressed as people who don’t have it.
10 Questions to Ask Your Doctor About Diabetes
If you have recently been diagnosed with type 2 diabetes, ask your doctor the following questions at your next visit.
- Does having diabetes mean that I am at increased risk for other medical problems?
- Do I need to see another doctor, such as an eye doctor, regularly?
- How often should I measure my blood sugar and what should I do if my blood sugar is too high or too low?
- Are there any new drugs that can be used to treat diabetes?
- Does diabetes mean I have to stop eating my favorite food?
- How can exercise affect diabetes?
- If I am overweight, how many pounds do I need to lose to improve my health?
- Are my children at increased risk of getting sick?
- What is the importance of diet in diabetes?
- Should I take the medicine even on a good day?