Type 2 diabetes occurs when blood sugar levels rise due to issues with how the body uses or produces insulin. Symptoms may include frequent urination, increased thirst, and blurry vision.

It can appear at any age, but it is more likely to occur after the age of 45 years. In 2019, 37.3 million Americans had diabetes, mostly type 2.

This article examines the early signs and symptoms of type 2 diabetes, the risk factors, and potential complications.

Type 2 diabetes occurs when a person’s body no longer responds to insulin correctly. This is called insulin resistance. After some time, the pancreas makes less and less insulin.

Insulin is a hormone that regulates the movement of blood glucose, or sugar, into cells, which use it as energy.

When sugar cannot enter cells, too much glucose collects in the blood, and the body cannot use it for energy.

A doctor may diagnose diabetes if a person’s blood sugar levels are 126 milligrams per deciliter (mg/dl) or above after fasting for 8 hours.

What are the risk factors for diabetes?

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The symptoms of high blood sugar in type 2 diabetes tend to appear gradually. Not everyone will notice symptoms in the early stages, but they may appear over time.

If symptoms do occur, they may include the following:

Frequent urination and increased thirst

When too much glucose builds up in the bloodstream, the kidneys cannot reabsorb it. The body removes the excess glucose in the urine, taking water from the body with it. This can lead to excessive thirst and the need to drink and urinate more.

Weight loss

When there is too little insulin, the body may start burning fat and muscle for energy. This causes weight loss.


When cells lack glucose, the body becomes tired. Fatigue can interfere with daily life when a person has type 2 diabetes.

Blurred vision

High blood glucose can cause fluid to be pulled from the lenses of the eyes, resulting in swelling, and leading to temporarily blurred vision.

Infections and sores

A person may notice itching around the penis or vagina or frequent Candida infections. Infections and sores may take longer to resolve because diabetes impacts blood circulation.

If people notice these symptoms, they should consult a doctor. Diabetes can lead to several serious complications. The sooner a person starts managing glucose levels, the better the chance of preventing complications.

Symptoms in children and teens

Type 2 diabetes is more likely to appear after the age of 45 years, but it can affect children and teens who:

  • have a high body mass index (BMI) for their age
  • do not do much physical activity
  • have high blood pressure
  • have a family history of type 2 diabetes
  • are Black American, Asian American, Hispanic American, or Native American

Symptoms will be the same as for adults, as mentioned above.

If a child or teen has these symptoms, they should talk with a doctor. They may be signs of type 2 diabetes but can also indicate type 1 diabetes.

Type 1 is less common but more likely to affect children and teenagers than adults.

Learn more about how diabetes affects children and teens and how to spot the symptoms early.

Symptoms in older adults

Around 29.2% of people aged 65 and above have type 2 diabetes in the United States. They may have some or all the classic symptoms of type 2 diabetes.

They may also experience one or more of the following:

  • flu-like fatigue, which includes feeling lethargic and chronically weak
  • urinary tract infections
  • numbness and tingling in the hands, arms, legs, and feet due to circulation and nerve damage
  • dental problems, including infections of the mouth and red, inflamed gums

Diabetes can lead to a range of skin changes, some of which may be early warning signs.

Examples include:

  • acanthosis nigricans, areas of darker, velvety skin, especially on the neck, elbows, knees, and knuckles
  • necrobiosis lipoidica, raised patches that may be yellow, red, brown, or darker than the surrounding skin and that may become swollen and hard
  • digital sclerosis, when hard, thickening, or swollen skin appears on the hands, possibly spreading to the arms and elsewhere
  • painless blisters that suddenly appear
  • wounds that take longer to heal
  • frequent skin infections

Learn more about the early signs of type 2 diabetes.


A person with prediabetes will not have any symptoms, but they will have blood sugar levels of 100–125 mg/dl.

Their blood sugar levels are high, but they do not have diabetes. Taking action at this stage can prevent diabetes from developing.

The Centers for Disease Control Prevention (CDC) estimate that around 96 million American adults have prediabetes, but 80% do not know they have it.

Diabetes may cause a number of health complications if people are unable to manage it. Many are long term, but some need immediate medical attention.

Emergency complications

Complications can arise quickly if blood sugar rises or falls too far.


Hypoglycemia, or low blood sugar, is when blood glucose dips below 70 mg/dl.

This can happen if a person who uses insulin takes more than they need for a particular time. It can also occur with other medications that treat diabetes, such as sulfonylureas.

A home blood glucose test can check for hypoglycemia.

It is vital to know the early signs of hypoglycemia, as it can progress quickly, resulting in seizures and a coma. In the early stages, however, it is easy to treat.

Symptoms of hypoglycemia include:

If symptoms are mild, a person can often resolve low blood sugar levels by consuming 15 grams (g) of carbohydrates, for example, by consuming:

  • 4 ounces of orange juice
  • 4 glucose tablets
  • a tablespoon of honey or sugar

The person should then wait 15 minutes, test their blood sugar, and if it is still low, repeat the process with another 15 g of carbohydrates.

When levels return to above 70 mg/dl, the person should eat a meal, to stabilize their glucose levels.

If glucose levels remain low or symptoms worsen, someone should take the person to the emergency room.

Anyone who has frequent or severe hypoglycemic episodes should speak with a doctor, as they may need to adjust their treatment plan.

Hyperglycemia and diabetic ketoacidosis (DKA)

If blood sugar levels rise too far, hyperglycemia can result. If a person notices increased thirst and urination they should check their blood sugar levels.

If the level is above the target level agreed with a doctor, the person should do some exercise to reduce the level.

However, a person should not exercise if their blood glucose levels are 240 ml/dl or above, as this could be a sign of diabetic ketoacidosis (DKA).

DKA can develop if a person has hyperglycemia and does not take action to reduce it. DKA happens when high levels of ketones collect in the blood, making it too acidic. For this reason, the person should also test their ketone levels.

Ketoacidosis can lead to:

A person with these signs and symptoms should seek immediate medical attention, as DKA can be life threatening.

People who regularly experience high blood sugar should discuss adjusting their treatment plan with their doctor.

What types of diabetic emergencies are there?

Long-term complications

Keeping blood glucose within target levels can prevent long-term complications.

Here are some complications that can arise:

Effective management of blood glucose levels can reduce the risk of complications.

A doctor can diagnose type 2 diabetes with a range of blood tests that measure blood glucose levels. Many people discover they have high blood sugar during a routine screening test, but anyone who experiences symptoms should see a doctor.

Which tests do doctors use to diagnose diabetes?

Treatment aims to keep blood glucose levels stable at a healthy level and prevent complications. The main ways to do this are through lifestyle measures.

These include:

  • following a diabetes meal plan agreed with the healthcare team
  • eating plenty of fresh fruits and vegetables
  • reaching and maintaining a suitable BMI
  • doing physical activity
  • getting enough sleep
  • avoiding or quitting smoking
  • taking medications or insulin as the doctor recommends
  • attending routine medical visits and blood tests

Some herbs and supplements may also help.

Find out more about the different types of diabetes and their treatment options.

There is currently no cure for diabetes, but lifestyle measures can help most people manage their blood sugar levels and reduce the risk of complications. If these do not help, a doctor may prescribe medication.

People who receive a diagnosis of prediabetes may be able to slow, stop, or reverse the progress of diabetes.

If a person is unable to manage their blood glucose levels, complications can arise. Some of these can be life threatening.

Here are some questions people often ask about type 2 diabetes.

What is type 2 diabetes caused by?

Type 2 diabetes is caused by problems with a chemical in the body (hormone) called insulin.

It’s often linked to being overweight or inactive, or having a family history of type 2 diabetes.

What is the difference between type 1 and 2 diabetes?

Type 1 diabetes is a lifelong condition where the body’s immune system attacks and destroys the cells that produce insulin.

Meanwhile, type 2 diabetes is when the body does not produce enough insulin, or the body’s cells do not react to insulin properly.

There is no cure for type 1 diabetes but type 2 can be prevented and it can potentially be put into remission.

Is type 2 diabetes curable?

There is no cure for diabetes, but lifestyle measures, such as exercise and dietary choices, can help manage it. In some cases, a person may need medication.

What are the warning signs of type 2 diabetes?

Often, the first time a person knows they have type 2 diabetes is after a routine blood test, possibly for another condition. If symptoms occur, they include an increased need to urinate, thirst, fatigue, blurry vision, and feeling hungrier than usual.

How does type 2 diabetes start?

Type 2 diabetes starts when the body becomes unable to use insulin effectively. The body produces more insulin to help itself process glucose in the blood. Over time, the body can no longer make enough insulin, and blood glucose levels rise. This can lead to complications.

Type 2 diabetes often has no symptoms in the early stages, and people often find out they have it during a routine blood test.

If symptoms appear, they include feeling thirsty and needing to urinate more often, having frequent infections, fatigue, and unexplained weight loss.

Current guidelines recommend regular screening from the age of 45 years or younger if an individual has other risk factors, such as obesity. A doctor can advise on individual needs.

Anyone who has concerns about diabetes should seek medical advice. An early diagnosis can help slow the progression of type 2 diabetes and prevent complications.