2.3 List the most common possible causes of diabetes

This guide will help you answer 2.3 List the most common possible causes of diabetes.

Diabetes is a long-term medical condition that affects how the body processes blood sugar, known as glucose. Glucose is an important source of energy for the body’s cells. Insulin, a hormone produced by the pancreas, helps move glucose from the blood into the cells. With diabetes, the body either does not make enough insulin or cannot use it effectively. This causes glucose to build up in the blood.

There are two main types of diabetes:

• Type 1 diabetes
• Type 2 diabetes

There is also gestational diabetes which develops during pregnancy. While the types have different causes, they share some common risk factors that contribute to the development of the condition.

This guide covers the most common causes and contributing factors to the onset and progression of diabetes.

Causes of Type 1 Diabetes

Type 1 diabetes is an autoimmune condition. The immune system attacks and destroys insulin-producing cells in the pancreas. The exact reason this happens is not fully understood. However, research shows several factors can increase the likelihood of developing it.

Autoimmune Reaction

The immune system mistakenly recognises the insulin-producing cells as harmful and destroys them. This is not triggered by lifestyle or diet. It often happens suddenly.

Genetic Factors

Family history plays a strong role. People with close relatives who have type 1 diabetes have a higher risk. Certain genes make the immune system more likely to attack the pancreas.

Viral Infections

Some viruses may trigger the autoimmune reaction that causes type 1 diabetes. Examples include measles, mumps and Coxsackie B virus. The viral infection may cause changes in the immune system that lead to its mistaken attack on healthy cells.

Environmental Factors

Factors in the environment, such as toxins or early exposure to certain dietary proteins, are being studied as possible triggers. The link is not yet proven but could explain why type 1 diabetes can occur even in people with no family history.

Causes of Type 2 Diabetes

Type 2 diabetes often develops gradually. It is more common than type 1 diabetes. In this type, the pancreas may still produce insulin. The problem is that the body’s cells do not respond to it properly. This is called insulin resistance. Over time, the pancreas struggles to keep up and blood sugar rises.

There are many well-known causes and contributing factors linked to type 2 diabetes.

Insulin Resistance

Cells in the muscles, liver and fat tissue stop responding effectively to insulin. The pancreas produces more insulin to try to move glucose into the cells. This extra demand on the pancreas eventually reduces its ability to produce insulin, leading to high blood sugar levels.

Genetics and Family History

A strong link exists between family history and type 2 diabetes risk. Specific genes influence how the body makes and uses insulin. Having a parent or sibling with type 2 diabetes increases the chance of developing the condition.

Being Overweight or Obese

Excess body fat, especially around the abdomen, is a key cause of insulin resistance. This is because abdominal fat releases chemicals that can affect how the body processes glucose. People with higher body mass index (BMI) are more likely to develop type 2 diabetes.

Physical Inactivity

Low levels of physical activity contribute to weight gain and can reduce insulin sensitivity. Regular exercise helps cells use glucose better and keeps weight in a healthy range.

Unhealthy Diet

A high intake of processed foods, sugary drinks and refined carbohydrates is linked to higher risk. This type of diet causes rapid spikes and drops in blood sugar, which over time may lead to insulin resistance. Diets lacking in fibre, fruits and vegetables can contribute to the problem.

Age

The risk of type 2 diabetes increases with age. This is linked to reduced muscle mass, lower physical activity levels and gradual decline in insulin function. However, younger people can also develop it if other risk factors are present.

High Blood Pressure and Cholesterol Problems

These are often part of a group of conditions known as metabolic syndrome. Having metabolic syndrome increases the risk of type 2 diabetes because it is linked to insulin resistance and cardiovascular health problems.

Ethnic Background

Certain ethnic groups have higher risk levels of type 2 diabetes, including South Asian, African-Caribbean and Chinese backgrounds. This may be linked to genetic factors and how the body handles glucose.

Causes of Gestational Diabetes

Gestational diabetes occurs during pregnancy. Hormonal changes make it harder for the body to use insulin. The placenta produces hormones that can block the action of insulin. If the pancreas cannot make enough extra insulin, blood sugar levels rise.

Pregnancy Hormones

Hormones such as human placental lactogen, cortisol and oestrogen increase during pregnancy. These can make the cells in the body less responsive to insulin.

Overweight Before Pregnancy

Women who are overweight before becoming pregnant face a greater risk of gestational diabetes. This is linked to higher levels of insulin resistance before pregnancy.

Family History

A family history of type 2 diabetes or gestational diabetes increases risk. Both genetic factors and shared lifestyle patterns can play a part.

Previous Gestational Diabetes

Women who have had the condition in a prior pregnancy are more likely to have it again.

Older Maternal Age

Pregnant women aged 25 or over have a slightly greater chance of developing gestational diabetes.

Lifestyle and Environmental Factors Common to All Types

While the immediate cause of each type of diabetes varies, some common factors contribute across types.

• Unhealthy eating patterns
• Weight gain and obesity
• Lack of physical activity
• Stress-related hormonal changes
• Certain medication side effects
• High levels of certain environmental toxins

Some medications, such as long-term corticosteroid use, can raise blood sugar levels. Exposure to chemicals such as pesticides has been linked in some studies to increased risk.

Less Common Causes and Contributing Factors

Not all diabetes cases are linked to the most widely known causes. In some situations, more unusual triggers are involved.

Pancreatic Diseases and Injuries

Conditions like pancreatitis, pancreatic cancer or surgery on the pancreas can reduce insulin production because they damage pancreatic tissue.

Hormonal Disorders

Certain endocrine disorders cause hormone imbalances that can lead to diabetes. For example, Cushing’s syndrome causes excess cortisol, which can raise blood glucose.

Genetic Syndromes

Rare genetic syndromes such as Wolfram syndrome or cystic fibrosis can cause diabetes by affecting insulin production or use.

Medications

Some drugs used for other conditions can cause high blood sugar by affecting insulin resistance or glucose production. Examples include certain antipsychotics and diuretics.

Preventing and Managing Risk Factors

For type 1 diabetes prevention is not currently possible because it is triggered by autoimmune reactions. For type 2 diabetes and gestational diabetes, positive lifestyle changes can reduce risk.

Ways to lower risk include:

• Eating a balanced diet rich in whole grains, fruits, vegetables and lean proteins
• Keeping physically active with regular exercise
• Maintaining a healthy weight
• Managing stress to limit its impact on hormone levels
• Attending regular health checks to monitor blood sugar in high-risk individuals

Awareness of personal and family health history can help identify early signs and make changes sooner.

Final Thoughts

Diabetes can develop through different routes. For type 1 diabetes the immune system and genetics play the strongest role. For type 2 and gestational diabetes lifestyle, weight and diet have a greater influence. Understanding these causes helps health and social care workers support individuals with risk factors. This includes giving guidance on healthier living and promoting early testing for those who could be at risk.

For care workers, recognising the most common causes is a key part of providing effective person-centred support. Discussing the reasons with individuals helps them understand their condition and empowers them to make changes that improve their long-term health. By linking knowledge about causes to practical advice, workers can make a real difference in preventing complications and improving quality of life.