Diabetes Demystified: Types, Causes and Management

Diabetes is a complex and increasingly prevalent condition that affects millions of people worldwide. Despite its widespread impact, there remains considerable confusion surrounding its various forms, causes and treatment options. 

According to Diabetes UK, it is estimated that more than 5.6 million people in the UK are living with diabetes, which is an all-time high.

This article aims to break down the complexities of diabetes, offering a clear and comprehensive understanding of the condition. In this guide, we will explore the different types of diabetes, from Type 1 and Type 2 to gestational and other rarer forms, delve into the root causes of each, and provide insights into the latest management strategies. 

Whether you are newly diagnosed, caring for a loved one with the condition, or simply seeking to understand this condition, this guide serves as a resource to empower you with the knowledge needed to navigate diabetes effectively. With the right information and tools, diabetes can be managed, and individuals can lead fulfilling, healthy lives.

Understanding Diabetes

Diabetes is a chronic medical condition characterised by the body’s inability to properly regulate blood glucose (sugar) levels. This dysregulation is primarily due to problems with insulin, which is a hormone produced by the pancreas that helps cells absorb glucose from the bloodstream to use for energy.

Without enough insulin or when the body becomes resistant to it, glucose accumulates in the bloodstream because it cannot enter cells efficiently. This leads to hyperglycaemia (high blood sugar). Over time, prolonged high blood sugar levels damage organs, blood vessels and nerves, contributing to long-term health complications.

Diabetes has become a global epidemic, affecting over 537 million adults worldwide as of 2021. This number is expected to rise to 783 million by 2045, with significant increases in low- and middle-income countries due to urbanisation, sedentary lifestyles and increased consumption of unhealthy diets.

Diabetes is one of the most costly chronic conditions due to healthcare expenditures related to treatment, management of complications, and indirect costs like lost productivity. People with diabetes often face significant lifestyle changes, frequent medical check-ups, and the possibility of debilitating complications, which reduce overall quality of life.

Managing diabetes requires continuous medical attention and support, placing a tremendous burden on healthcare systems globally. Countries with limited healthcare resources particularly struggle to provide adequate care.

When diabetes is not managed well, either through poor blood glucose control or inadequate treatment, it can lead to severe long-term complications that affect multiple organ systems. These include:

• Cardiovascular disease – people with diabetes are at significantly higher risk for heart disease, including heart attacks and strokes, due to damage to blood vessels and increased risk of atherosclerosis (hardening of the arteries).
• Kidney failure – high blood sugar can damage the kidneys’ filtering system, leading to chronic kidney disease and, in severe cases, end-stage renal disease requiring dialysis or transplantation.
• Nerve damage – nerve damage is common, particularly in the extremities, causing symptoms like tingling, pain or loss of sensation. This can lead to foot ulcers and, in severe cases, amputation.
• Vision problems – prolonged high blood sugar can damage blood vessels in the retina, leading to vision impairment or blindness. People with diabetes are also more prone to cataracts and glaucoma.

Diabetes is not only a personal health challenge but a growing global public health crisis. It requires comprehensive management to prevent debilitating complications and improve long-term health outcomes. 

Types of Diabetes

Type 1 Diabetes

Type 1 diabetes is a chronic condition in which the pancreas produces little or no insulin, a hormone essential for converting sugar (glucose), starches and other food into energy. It is an autoimmune disease, meaning the body’s immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas.

Type 1 diabetes often develops in children, teenagers or young adults, usually between the ages of 4 and 14. However, onset can happen in infants or even later in adulthood. The exact cause of Type 1 diabetes is not fully understood, but it is believed to involve genetic and environmental factors. Viral infections may also trigger the autoimmune response.

Common symptoms include:

• Frequent urination
• Extreme thirst
• Unintended weight loss
• Fatigue
• Blurred vision
• Increased hunger

Type 1 diabetes is diagnosed through blood tests that measure blood sugar levels. Tests may include:

• Fasting blood glucose test
• Oral glucose tolerance test
• A1C test (average blood sugar levels over the past two to three months)

Type 1 diabetes requires lifelong management, which typically includes:

• Insulin therapy – people with Type 1 diabetes need to take insulin daily, either through injections or an insulin pump.
• Blood sugar monitoring – regular monitoring of blood glucose levels to ensure they remain within a target range.
• Diet and exercise – a balanced diet and regular physical activity are crucial for managing blood sugar levels.

If not managed properly, Type 1 diabetes can lead to various complications, including:

• Heart disease
• Kidney damage
• Nerve damage
• Eye damage
• Increased risk of infection

People can lead healthy lives with proper management, education and support. Continuous glucose monitors and advancements in insulin delivery systems are improving the quality of life for those with Type 1 diabetes.

While Type 1 diabetes is a serious condition, advances in treatment and management have made it possible for those affected to maintain a good quality of life. Regular check-ups and a support network can greatly aid in managing the condition effectively.

Type 2 Diabetes

Type 2 diabetes is a chronic condition that affects how the body processes blood sugar (glucose). It’s the most common form of diabetes, and it primarily develops in adults, although it’s increasingly being diagnosed in younger people as well.

In Type 2 diabetes, the body either becomes resistant to insulin, a hormone that helps regulate glucose levels, or it doesn’t produce enough insulin to maintain normal blood sugar levels. As a result, glucose builds up in the bloodstream instead of being used by the cells for energy. Over time, this can lead to serious health problems, including heart disease, nerve damage, kidney damage and eye issues.

In Type 2 diabetes, muscle, fat and liver cells don’t respond well to insulin, leading to an inability to use glucose efficiently. The pancreas compensates by producing more insulin, but over time it can’t keep up. 

Risk factors include:

• A family history of Type 2 diabetes
• Poor diet
• Obesity
• Physical inactivity
• Being overweight

Symptoms include:

• Increased thirst
• Frequent urination
• Increased hunger
• Fatigue
• Blurred vision
• Slow-healing sores or infections
• Tingling or numbness in hands or feet

Many people with Type 2 diabetes may not have noticeable symptoms in the early stages, which is why regular blood tests are important for those at risk. It is diagnosed through blood tests such as:

• Fasting blood glucose test – this measures blood sugar after fasting overnight.
• Haemoglobin A1C test – this indicates average blood sugar levels over the past 2-3 months.
• Oral glucose tolerance test (OGTT) – this measures blood sugar levels before and after consuming a sugary drink.

Eating a balanced diet that focuses on vegetables, whole grains, lean proteins and healthy fats, and reducing processed foods and refined sugars, is essential. Regular physical activity improves insulin sensitivity and helps manage blood sugar levels. Even a modest reduction in body weight can improve blood sugar control.

Metformin is a common first-line drug that reduces glucose production in the liver and improves insulin sensitivity. In some cases, people with Type 2 diabetes may need insulin therapy. Regular blood sugar checks are crucial to managing the condition effectively.

If not well-controlled, Type 2 diabetes can lead to long-term complications, such as:

• Cardiovascular disease
• Nerve damage
• Kidney damage
• Eye damage
• Foot problems due to poor circulation

Early diagnosis and proper management of Type 2 diabetes can prevent or delay these complications and improve overall quality of life.

Gestational Diabetes

Gestational diabetes is a type of diabetes that develops during pregnancy and typically goes away after the baby is born. It occurs when the body is unable to produce enough insulin to regulate blood sugar (glucose) levels during pregnancy. Insulin is a hormone that helps cells take in glucose from the blood, and during pregnancy, the body’s insulin needs increase. If the body can’t meet this demand, blood sugar levels rise, leading to gestational diabetes.

Gestational diabetes is diagnosed through glucose screening tests, such as:

• Glucose challenge test – a simple screening where a woman drinks a sugary drink, and her blood sugar is tested an hour later.
• Oral glucose tolerance test (OGTT) – if the glucose challenge test shows high blood sugar levels, a follow-up OGTT is done to confirm the diagnosis.

It can lead to a large birth weight for the baby, which increases the risk of complications during delivery, preterm birth, low blood sugar at birth, and respiratory distress syndrome. Babies born to mothers with gestational diabetes also have a higher risk of developing obesity or Type 2 diabetes later in life.

For the mother, there is an increased risk of high blood pressure, preeclampsia, and the development of Type 2 diabetes after pregnancy. Gestational diabetes can usually be managed through a combination of:

• Dietary changes – a balanced diet focusing on controlling carbohydrate intake.
• Regular physical activity – exercise helps improve insulin sensitivity and control blood sugar levels.
• Monitoring blood sugar – women may need to check their blood sugar levels regularly.
• Medication – if lifestyle changes are not enough, some women may need insulin or oral medications to manage their blood sugar levels.

Gestational diabetes usually resolves after childbirth, but women who have had it are at higher risk of developing Type 2 diabetes later in life. Therefore, postpartum follow-up is crucial.

Gestational Diabetes UK offer advice and support for anyone living with the condition.

Other Forms

Other forms of diabetes are generally less common and fall under specific categories of diabetes that have distinct causes or characteristics. The key ones are:

Maturity-Onset Diabetes of the Young (MODY)

MODY is a monogenic form of diabetes, meaning it results from mutations in a single gene. It often affects young adults or adolescents, and unlike Type 1, it is not autoimmune-related. MODY is characterised by insulin secretion defects but usually without insulin resistance or obesity. It is often misdiagnosed as Type 1 or Type 2 diabetes. MODY is typically treated with oral medications rather than insulin.

Neonatal Diabetes Mellitus (NDM)

This is a rare form of diabetes that occurs in infants under six months of age. It is caused by genetic mutations that affect insulin production. There are two types: transient neonatal diabetes, which resolves within a few months, and permanent neonatal diabetes, requiring lifelong treatment. Treatment usually involves insulin therapy.

Latent Autoimmune Diabetes in Adults (LADA)

LADA is a slow-progressing form of autoimmune diabetes, similar to Type 1, but it develops later in life, typically after age 30. Patients may initially be misdiagnosed as having Type 2 diabetes because they can manage blood sugar without insulin for some time. However, over time, their bodies lose the ability to produce insulin, and they require insulin therapy. Like Type 1, it eventually requires insulin treatment.

Steroid-induced diabetes

This form of diabetes is caused by the prolonged use of glucocorticoids (steroids), which can impair the body’s ability to regulate blood sugar. Blood sugar levels rise due to the medication rather than an underlying defect in insulin production or action. Adjusting steroid dosages or using diabetes medications, such as insulin or oral drugs, may help manage blood sugar.

Cystic Fibrosis-Related Diabetes (CFRD)

This form of diabetes affects people with cystic fibrosis (CF). It occurs because CF affects the pancreas, impairing its ability to produce insulin. It has features of both Type 1, due to lack of insulin production, and Type 2, because insulin resistance can also be present. Insulin is the most common treatment.

Post-Transplant Diabetes Mellitus (PTDM)

PTDM occurs after organ transplantation, largely due to the use of immunosuppressive drugs, like corticosteroids and calcineurin inhibitors that affect glucose metabolism. Patients develop high blood sugar post-transplant, and it shares similarities with Type 2 diabetes. Treatment often includes lifestyle changes and diabetes medications, including insulin if necessary.

Wolfram Syndrome (DIDMOAD)

This is a rare genetic disorder that causes insulin-dependent diabetes, optic atrophy, deafness and other neurological symptoms. It typically presents in childhood and is characterised by diabetes along with other complications such as progressive vision loss and hearing impairment. Insulin therapy for diabetes, along with supportive care for other symptoms, is usually helpful.

Type 3c Diabetes (Pancreatogenic Diabetes)

This type occurs when the pancreas is damaged due to pancreatitis, pancreatic surgery, trauma or diseases such as pancreatic cancer. Type 3c diabetes is caused by the pancreas’ inability to produce insulin and digestive enzymes. Treatment may involve both insulin and enzyme replacement therapies.

These forms of diabetes are rarer than the more common Type 1, Type 2 and gestational diabetes, but they highlight the complexity and variety of conditions that can affect blood sugar regulation. Each requires specific management strategies based on the underlying cause.

Causes and Risk Factors

Type 1 Diabetes

Type 1 diabetes is an autoimmune disease where the body’s immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. As a result, the pancreas can no longer produce sufficient insulin, a hormone essential for regulating blood glucose levels. This leads to chronic hyperglycaemia, which is the hallmark of diabetes. 

Several genetic factors play a critical role in the development of Type 1 diabetes. While genes predispose people, they are not sufficient alone to cause the disease. Environmental factors, including infections and other triggers, are often necessary to initiate the autoimmune process.

Environmental factors, particularly viral infections, are believed to play a significant role in triggering the autoimmune response in genetically susceptible individuals. The exact mechanisms are not fully understood.

• Coxsackievirus has been found in the pancreatic tissue of individuals with Type 1 diabetes, suggesting a direct viral role in beta cell destruction.
• Congenital rubella syndrome has been associated with an increased risk of Type 1 diabetes.
• Some evidence links Epstein-Barr virus infection with autoimmune diseases, including Type 1 diabetes.
• Cytomegalovirus (CMV) is another virus that may contribute to beta cell destruction, though the evidence is less robust than for coxsackievirus.
• Some studies suggest that rotavirus infections may trigger Type 1 diabetes, potentially through an interaction with gut immunity and systemic inflammation.

Besides viral infections, other environmental factors have been suggested as possible triggers for Type 1 diabetes:

• Early introduction of cow’s milk or gluten in infants may increase the risk, though this is still debated.
• Certain chemicals or toxins may damage beta cells or trigger immune responses that lead to Type 1 diabetes.
• Alterations in the gut microbiome, influenced by factors such as diet or antibiotic use, may play a role in immune dysregulation and the development of Type 1 diabetes.

Type 2 Diabetes

Unlike Type 1 diabetes, which is primarily due to autoimmune destruction of insulin-producing cells, Type 2 diabetes develops due to a combination of genetic, lifestyle and environmental factors. The key risk factors include:

Obesity

This is one of the most significant risk factors for Type 2 diabetes. Excess body fat, particularly visceral fat (around the abdomen), contributes to insulin resistance. This occurs because fat cells, especially in large quantities, release pro-inflammatory substances that interfere with the insulin signalling pathway. This disruption makes it harder for the body to regulate blood glucose levels, increasing the likelihood of developing diabetes.

Insulin resistance

As fat tissue increases, the body’s cells become less responsive to insulin, requiring more insulin to maintain normal blood glucose levels. Over time, the pancreas cannot produce enough insulin to compensate for this resistance, leading to hyperglycaemia.

Sedentary lifestyle

A lack of physical activity is another major risk factor for Type 2 diabetes. Regular exercise improves insulin sensitivity, enhances glucose uptake by muscles, and helps maintain a healthy weight. Sedentary individuals often have increased body fat and reduced muscle mass, both of which contribute to poor glucose control.

Poor diet

Diets high in refined carbohydrates, sugary beverages and unhealthy fats can contribute to obesity and insulin resistance, increasing the risk of Type 2 diabetes. Highly processed foods with added sugars and low fibre content cause rapid spikes in blood glucose levels, stressing the pancreas to produce more insulin.
To read about the importance of healthy eating, please see our knowledge base.

Family history and genetics

A family history of Type 2 diabetes significantly raises an individual’s risk of developing the condition. If a parent or sibling has the disease, genetic factors increase the likelihood of inheriting insulin resistance or impaired insulin secretion. However, environmental and lifestyle factors also interact with genetic predispositions, making prevention possible even in high-risk individuals. Variations in genes related to insulin production or glucose metabolism can predispose a person to diabetes; however, the condition’s onset can often be delayed or prevented with healthy lifestyle changes.

Age

The risk of developing Type 2 diabetes increases with age, especially after age 45. As people age, they tend to gain weight and lose muscle mass, both of which contribute to insulin resistance. Additionally, older individuals may be less physically active, further exacerbating their risk.

Historically, Type 2 diabetes was considered a condition affecting middle-aged and older adults. However, the growing prevalence of obesity and poor lifestyle habits among younger populations has shifted this trend.

The key factors contributing to Type 2 diabetes in younger people include:

Rising childhood obesity

The global rise in childhood and adolescent obesity is one of the most alarming trends linked to the increase in Type 2 diabetes cases in younger populations. Overweight and obese children are at a higher risk of developing insulin resistance, even in early life, setting the stage for Type 2 diabetes.

Poor dietary habits in children and adolescents

Younger populations are increasingly exposed to unhealthy food environments, which promote the consumption of processed foods high in sugars, unhealthy fats and refined carbohydrates. Fast food, sugary snacks and beverages have become staples in many children’s diets, contributing to excessive weight gain and metabolic issues.

Sedentary lifestyles among youth

Children and adolescents are spending more time engaging in sedentary activities, such as playing video games, using smartphones, and watching television. This lack of physical activity, combined with poor dietary choices, leads to an energy imbalance, resulting in weight gain and an increased risk of Type 2 diabetes.

Psychosocial stress and sleep deprivation

In recent years, young people have faced rising levels of stress, which can contribute to unhealthy behaviours like overeating or lack of physical activity. Sleep deprivation, which is increasingly common among teenagers, also plays a role in increasing the risk of insulin resistance and obesity.

Gestational Diabetes

The exact cause of gestational diabetes isn’t fully understood, but it is believed to be linked to hormonal changes during pregnancy. The placenta produces hormones that can interfere with insulin function, making it harder for the body to control blood sugar levels.

Risk factors include:

• Being overweight or obese.
• A history of gestational diabetes in a previous pregnancy.
• Family history of Type 2 diabetes.
• Being over the age of 25 during pregnan
• Having polycystic ovary syndrome (PCOS).
• Being of certain ethnic backgrounds, such as African American, Hispanic, Native American, or Asian.

Gestational diabetes often does not cause noticeable symptoms, which is why it is usually detected through routine glucose testing between the 24th and 28th weeks of pregnancy. However, some women may experience increased thirst, frequent urination, fatigue or blurred vision.

Managing Diabetes

Lifestyle Changes

Diet plays a critical role in managing diabetes, particularly Type 2 diabetes, where insulin resistance and poor glucose regulation are common challenges. A well-balanced diet helps to stabilise blood sugar levels, improve insulin sensitivity and prevent complications. The following components are key:

• Balanced meals – a healthy diabetes-friendly meal should contain a mix of carbohydrates, proteins and fats. Incorporating fibre-rich foods is essential, as fibre slows the absorption of sugar into the bloodstream, preventing spikes.
• Portion control – eating large portions, even of healthy foods, can lead to blood sugar fluctuations. Portion control helps to manage calorific intake and glucose levels.
• Carbohydrate monitoring – carbohydrates have the most significant impact on blood glucose levels, making it vital to monitor and manage their intake. The goal is to choose complex carbohydrates, which are digested slowly, like whole grains, legumes and non-starchy vegetables.
• Regular physical activity – this is one of the most effective ways to improve insulin sensitivity and control blood glucose levels. Exercise helps muscles use glucose more efficiently, reducing insulin resistance. This means that less insulin is needed to lower blood sugar levels, which is beneficial for both Type 1 and Type 2 diabetes patients.
• Monitor blood glucose regularly – monitoring blood sugar levels before and after meals and physical activity can help you understand how food and exercise affect your diabetes. This information can be used to make adjustments in your diet, portion sizes and activity level to maintain better control over glucose levels.

Medication and Insulin Therapy

Type 2 diabetes is typically managed with lifestyle changes and medications aimed at lowering blood sugar levels. The medications for Type 2 diabetes include medication taken by mouth and injectable therapies, including insulin and other non-insulin. 

Though insulin therapy is more commonly associated with Type 1 diabetes, some people with Type 2 diabetes may require insulin therapy, especially if other medications are insufficient or the disease progresses. Insulin may be used in combination with oral agents or as the sole treatment, particularly in people with long-standing Type 2 diabetes, those with high blood sugar levels, or during stressful periods like surgery or illness.

In Type 1 diabetes, insulin therapy is lifelong and critical for survival. It is typically administered through multiple daily injections or insulin pumps, allowing for precise control of blood sugar.

While Type 2 diabetes is initially managed with oral medications and non-insulin injectable medication, insulin therapy may be needed as the disease progresses. Insulin therapy for Type 2 diabetes can involve long-acting insulin to control fasting glucose levels or a combination of long-acting and rapid-acting insulin to manage both fasting and post-meal blood sugars.

The management of diabetes, whether Type 1 or Type 2, requires a comprehensive approach. In Type 1 diabetes, insulin therapy is essential for survival, while in Type 2 diabetes, insulin may become necessary if other medications become insufficient. Each patient’s therapy is tailored based on individual needs, goals and the progression of their condition.

Monitoring and Preventive Care

Regular health check-ups are critical in managing diabetes and preventing its complications. Diabetes can affect multiple systems in the body, and early detection of issues can significantly reduce the risk of serious complications. Key aspects of health management for people with diabetes include HbA1c tests, eye exams and foot care, which together play a crucial role in preventing the long-term damage caused by the disease.

The HbA1c test measures the average blood glucose levels over the past 2-3 months, providing a broader view of diabetes control compared to daily blood sugar tests. Keeping HbA1c levels within the recommended range helps reduce the risk of diabetes-related complications. Regular monitoring of HbA1c allows healthcare providers to adjust treatment plans to better manage blood sugar levels, reducing the risk of high glucose levels or dangerous lows.

Diabetes can cause diabetic retinopathy, a condition where high blood sugar levels damage the blood vessels in the retina. Over time, this can lead to vision problems and even blindness. Annual eye exams are crucial because retinal damage often occurs without early symptoms. Early detection through eye exams can allow for interventions like laser treatment or injections that can slow or stop progression. Diabetes also increases the risk of other eye diseases, including glaucoma and cataracts, both of which can be managed if detected early. By scheduling regular eye exams, people with diabetes can prevent or minimise vision loss.

Diabetes can lead to peripheral neuropathy (nerve damage), especially in the feet. This can cause loss of sensation, making it harder to detect cuts, blisters or infections, which can worsen and lead to serious complications such as ulcers or, in severe cases, amputation. Additionally, poor blood circulation (peripheral artery disease) may impair healing in the feet. To prevent such issues, people with diabetes should perform daily foot checks for injuries or signs of infection, schedule regular podiatry visits, and wear well-fitting shoes to prevent pressure sores or blisters.

Regular health check-ups are essential in diabetes management. These proactive steps help in early detection and timely intervention, which can prevent severe complications such as blindness, heart disease, kidney failure, nerve damage and amputations. Comprehensive care empowers individuals with diabetes to lead healthier lives and reduce the overall impact of the disease.

Living Well with Diabetes

Living a full and active life with diabetes is absolutely possible with mindful management and the right strategies. Here are some key tips to help individuals with diabetes thrive while keeping their condition under control:

• Maintain a healthy, balanced diet.
• Stay physically active.
• Monitor blood sugar.
• Take medications as prescribed.
• Stay hydrated.
• Manage stress.
• Surround yourself with a support network of family, friends or diabetes support groups.
• Get regular check-ups.
• Always have a diabetes kit with you, including glucose tablets, snacks, insulin and testing supplies.
• Educate yourself about your condition.
• Seek mental health support if you feel stressed or overwhelmed.

Conclusion

Effective management of diabetes is paramount for maintaining a good quality of life and reducing the risk of complications. Through lifestyle modifications, such as a balanced diet and regular exercise, alongside medical interventions, individuals can successfully control their blood sugar levels and navigate their condition. 

Education and awareness remain critical, not only for those diagnosed but also for society at large, fostering an environment of support and understanding.

Diabetes UK run local support groups for people living with diabetes, and also take part in many other activities such as fundraising, campaigning and raising awareness.