Type 2 diabetes

Sometimes, too much sugar stays in your blood. This can happen if your body cannot use it well.

You might feel very thirsty. You might also feel very hungry. Some people feel very tired or lose weight.

This can happen if you do not move much. It can also happen if you eat too much sugar.

Doctors can check your blood to find out. Eating healthy food can help you stay well.

Staying active is a great way to help your body.

Type 2 diabetes is a condition where blood sugar levels stay too high. This happens for two main reasons. First, the body has insulin resistance. This means cells do not respond well to insulin. Insulin is a tool that helps cells use sugar for power. Second, the body may not make enough insulin.

Many people do not feel sick at first. Later, they might feel very thirsty or hungry. Some people feel tired or lose weight. They might also have sores that heal slowly. If blood sugar stays high for a long time, it can cause big problems. It can hurt the heart, kidneys, or eyes. It can even lead to blindness.

Many things can lead to this disease. Being overweight and not exercising are big factors. Some people are also at risk because of their genes.

Doctors use blood tests to find it. You can help prevent it by eating healthy food. Eating fruits and vegetables is good. Staying active also helps. Some people may need medicine or insulin shots to stay well.

Type 2 diabetes is a common health condition. It is a form of diabetes mellitus. This means blood sugar levels stay too high. It accounts for about 90% of all diabetes cases.

Other cases come from type 1 or gestational diabetes. This condition can lead to a ten-year shorter life expectancy. It often starts in middle or older age. However, rates are rising in young people too.

This condition works through two main problems. First, the body has insulin resistance. This means cells cannot respond well to insulin. Insulin is a tool that helps cells use sugar. Second, the body lacks enough insulin. The pancreas has special cells called beta cells. These cells make insulin for the body. In early stages, beta cells expand to help. Later, a person may lose half of these cells.

People have studied diabetes for a very long time. It was described in an ancient Egyptian manuscript. Between 400 and 500 CE, doctors saw two types. They knew type 1 was for youth. They saw type 2 was linked to being overweight. In the 1920s, scientists found the importance of insulin. Since 1960, cases have increased a lot. In 1985, there were 30 million cases. By 2015, there were 392 million cases.

Many symptoms can show that someone has diabetes. Common signs include thirst and frequent urination. People may feel hungry or very tired. Some might see unexplained weight loss. Other signs include slow-healing sores or pins and needles.

High blood sugar can cause serious long-term harm. It can lead to heart disease or stroke. It can also cause kidney failure or blindness. In some cases, it causes poor blood flow in legs. This might even lead to amputations.

Many things can change the risk of getting this disease. Lifestyle factors like obesity and lack of exercise are important. A diet high in sugar or saturated fat is a risk. Some people are also at risk because of their genes. About 72% of diabetes is inherited from parents. Doctors use blood tests to find the disease. They might check fasting plasma glucose levels. They can also use an A1c test. Staying active and eating healthy can help prevent it.

Type 2 diabetes (T2D) is a chronic medical condition characterized by high blood sugar levels. It is a specific form of diabetes mellitus. This disease is defined by insulin resistance and a relative lack of insulin. It accounts for approximately 90% of all diabetes cases globally. The remaining 10% of cases are primarily attributed to type 1 diabetes and gestational diabetes. Because it affects how the body uses energy, it is a major focus of modern medicine.

The biological mechanism involves a failure in how the body manages glucose. This usually happens through two connected processes: insulin resistance and beta cell dysfunction. Insulin resistance occurs when cells in the muscles, liver, and fat tissue cannot respond properly to insulin. At a molecular level, this is often caused by an impairment in the insulin signal transduction pathway. Specifically, the signaling cascade downstream of the insulin receptor becomes blocked. This can involve components like insulin receptor substrate (IRS) proteins or AKT. In the liver, this resistance causes the organ to inappropriately release glucose into the blood.

To manage this, the pancreas attempts to compensate. The pancreas contains specialized cells called beta cells that produce insulin. In the early stages of insulin resistance, the mass of these beta cells expands. They work harder to produce more insulin to overcome the cellular insensitivity. However, as the disease progresses, the beta cells can no longer keep up. By the time type 2 diabetes is fully manifest, a person may have lost about half of their beta cells. This creates a cycle where the body has both high resistance and insufficient insulin production.

Symptoms of type 2 diabetes can develop very slowly over many years. Classic signs include polyuria, which is frequent urination, and polydipsia, or increased thirst. Many people also experience polyphagia, which is increased hunger, alongside unexplained weight loss. Other common symptoms include fatigue, blurred vision, and a sensation of pins and needles. Some individuals may also notice sores that heal slowly or a loss of taste. Because symptoms are often subtle, many people are only diagnosed during routine medical testing.

If left unmanaged, high blood sugar leads to serious long-term complications. The risk of cardiovascular disease, including ischemic heart disease and stroke, is two to four times higher. Type 2 diabetes is also a leading cause of nontraumatic blindness and kidney failure in the developed world. It can cause diabetic retinopathy, which may lead to blindness. Poor blood flow in the lower limbs can also increase the risk of amputations by 20-fold. Additionally, the disease is associated with cognitive dysfunction, such as Alzheimer's disease and vascular dementia.

History shows that humans have recognized diabetes for millennia. One of the earliest descriptions appears in an ancient Egyptian manuscript from the BCE era. Between 400 and 500 CE, medical observers identified type 1 and type 2 as separate conditions. They noted that type 1 was associated with youth, while type 2 was linked to being overweight. A major breakthrough occurred in the 1920s when the importance of insulin was determined. Since 1960, the rates of type 2 diabetes have increased significantly alongside rising obesity rates. In 1985, there were roughly 30 million cases, but by 2015, that number rose to approximately 392 million.

Risk factors for the disease include both lifestyle and genetics. Lifestyle factors include obesity, a sedentary lifestyle, and diets high in saturated fats or sugar-sweetened drinks. Lack of sleep and psychological stress are also linked to the condition. Genetics play a massive role, as the proportion of diabetes that is inherited is estimated at 72%. Scientists have identified more than 36 genes that contribute to this risk. For example, the TCF7L2 allele can increase the risk of developing the disease by 1.5 times. Doctors diagnose the condition using blood tests like fasting plasma glucose or the glycated hemoglobin (A1c) test. Management often involves dietary changes, regular exercise, or medications like metformin.