What is Type 2 Diabetes?

Type 2 diabetes is a common metabolic condition that develops when the body fails to produce enough insulin or when insulin fails to work properly, which is referred to as insulin resistance. Insulin is the hormone that stimulates cells to uptake glucose from the blood to use for energy.

When this is the case, cells are not instructed by insulin to take up glucose from the blood, meaning the blood sugar level rises (referred to as hyperglycemia).

People usually develop type 2 diabetes after the age of 40 years, although people of South Asian origin are at an increased risk of the condition and may develop diabetes from the age of 25 onwards. The condition is also becoming increasingly common among children and adolescents across all populations. Type 2 diabetes often develops as a result of overweight, obesity and lack of physical activity and diabetes prevalence is on the rise worldwide as these problems become more widespread.

Type 2 diabetes accounts for approximately 90% of all diabetes cases (the other form being type 1 diabetes) and treatment approaches include lifestyle changes and the use of medication.

Understanding Type 2 Diabetes

Types of Diabetes

Also known of as juvenile diabetes, type 1 diabetes usually occurs in childhood or adolescence. In type 1 diabetes, the body fails to produce insulin. Patients have to be given the hormone, which is why the condition is also known of as insulin-dependent diabetes mellitus (IDDM).

Type 2 diabetes mellitus is also called non-insulin dependent diabetes mellitus (NIDDM), since it can be treated with lifestyle changes and/or types of medication other than insulin therapy. Type 2 diabetes is significantly more common than type 1 diabetes.

Symptoms of Type 2 Diabetes

The increased blood glucose level seen in diabetes can eventually damage a person’s blood vessels, nerves and organs. The body attempts to remove the excess glucose through urination and the most common symptoms of type 2 diabetes include the following:

  • Polydipsia (increased thirst)
  • Polyphagia (increased hunger)
  • Polyuria (increased frequency of urination), especially during the night
  • Extreme fatigue, weight loss and sudden loss of muscle bulk.

Some of these symptoms are also seen in type 1 diabetes, but type 2 diabetes symptoms tend to develop more gradually and can take months or years to manifest. This can make it more difficult for people to tell they have an underlying health condition and often people have had type 2 diabetes for a long time before it is finally diagnosed.

Risk Factors

Several factors can increase a person’s risk of developing diabetes. Examples include:

  • Overweight or obesity
  • Unhealthy diet
  • Waist measurement of 31.5 inches or more among women
  • Waist measurement of more than 37 inches among men
  • Low levels of physical activity
  • Raised cholesterol
  • High blood pressure
  • South Asian ethnicity
  • Smoking

A family history of the diabetes also increases a person’s risk of developing the condition. Studies have shown that the offspring of families where one parent has diabetes, are at a 15% increased risk of developing the condition and that offspring born to two parents with diabetes have a 75% increased risk.

Complications of Type 2 Diabetes

The high blood glucose seen in diabetes can damage blood vessels, nerves and organs, leading to a number of potential complications. Some examples of the complications caused by diabetes include the following:

Heart Disease and Stroke

A persistently high blood glucose level can increase the risk of blood vessels becoming narrowed and clogged with fatty plaques (atherosclerosis). This can disrupt blood flow to the heart causing angina and in some cases, heart attack. If blood vessels that supply the brain are affected, this can lead to stroke.

Nervous System Damage

Excess glucose in the blood can damage small blood vessels in the nerves causing a tingling sensation or pain in the fingers, toes and limbs. Nerves that lie outside of the central nervous system may also be damaged, which is referred to as peripheral neuropathy. If nerves of the gastrointestinal tract are affected, this may cause vomiting, constipation and diarrhea.

Diabetic Retinopathy

Damage to the retina may occur if tiny vessels in this layer of tissue become blocked or start to leak. Light then fails to pass through the retina properly which can cause vision loss.

Kidney Disease

Blockage and leakage of vessels in the kidneys can affect kidney function. This usually happens as a result of high blood pressure and blood pressure management is an important part of managing type 2 diabetes.

Foot Ulceration

Nerve damage in the feet can mean small cuts are not felt or treated, which can lead to a foot ulcer developing. This happens to around 10% of people with diabetes.

Prevention, Treatment and Care

Blood sugar should be regularly monitored so that any problems can be detected and treated early. Treatment involves lifestyle changes such as eating a healthy and balanced diet and regular physical exercise. If lifestyle changes alone are not enough to regulate the blood glucose level, anti-diabetic medication in the form of tablets or injections may be prescribed. In some cases, people who have had type 2 diabetes for many years are eventually prescribed insulin injections.

Maintaining a healthy blood glucose level, blood pressure and cholesterol is essential to preventing the complications of type 2 diabetes. Overweight or obese individuals with diabetes often significantly reduce the extent of their symptoms by making adjustments to their lifestyle.

Further Reading

Last Updated: Feb 27, 2019

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


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