Written by Dr. Matthew Capozzi, DPM, FACFAS, CWS (board-certified foot surgeon and wound specialist) · Medically reviewed by the CircuFiber Scientific Advisory Board · Updated: October 27, 2026

Diabetes is caused by the body either not making enough insulin or not responding to insulin properly, so glucose builds up in the blood instead of entering cells for energy. Type 1 diabetes is an autoimmune disease in which the immune system destroys the insulin-producing cells of the pancreas. Type 2 diabetes, which accounts for the large majority of cases, develops when insulin resistance combines with genetics, excess weight, inactivity and age. Gestational diabetes is caused by pregnancy hormones interfering with insulin. You do not "catch" diabetes, and sugar alone does not cause it, but diet, weight and activity strongly affect your risk of type 2.

Key Takeaways

• Diabetes is a chronic condition caused by inadequate insulin production or reduced insulin sensitivity, which leaves too much glucose in the bloodstream.
• Type 1 diabetes is caused by the immune system attacking insulin-producing cells in the pancreas; genetics and environmental triggers are both thought to play a role.
• Type 2 diabetes is caused by insulin resistance plus a combination of genetics, obesity, physical inactivity, poor nutrition and age.
• Gestational diabetes happens when pregnancy hormones interfere with the body's insulin response and not enough insulin is produced to keep glucose regulated.
• Risk factors you cannot change include family history, age, race and ethnicity; risk factors you can change include body weight, cholesterol, diet, activity and smoking.
• Uncontrolled diabetes damages blood vessels and nerves, raising the risk of heart disease, kidney disease and diabetic neuropathy, which is why prevention and management matter.

What is diabetes?

Diabetes is a persistent medical condition where the blood sugar levels are high due to either lack of enough insulin or complications in its sensitivity. It includes three primary types – type 1, type 2 and gestational diabetes – while a neonatal form affects newborn babies. Genetic and environmental components, along with age, race and ethnicity, may play an essential part in raising the risk of diabetes, which in turn increases the chances of heart disease, digestive and kidney diseases, and nerve damage.

Preventing and managing this illness can be done by opting for healthier habits, followed up with regular checking of glucose levels, and various other medically accepted treatments exist if needed.

What does insulin do?

Insulin is the hormone that lets glucose move out of the bloodstream and into your cells. The pancreas, found behind the stomach, produces insulin to enable glucose to be taken up by cells and aid in regulating blood sugar levels. When there is not enough of this hormone present, too much glucose remains in the bloodstream while an inadequate amount enters tissues for energy use, leading to high or low blood sugar concentrations as well as potential diabetes development if left unchecked. This makes understanding how insulin works all the more important when it comes to managing diabetes by ensuring appropriate glucose readings within our body at all times.

What does glucose do?

Glucose, a type of sugar essential for providing energy to cells in our bodies, is key for maintaining good health. Though typically used efficiently by the body, people with diabetes struggle to absorb and use glucose properly, which can lead to complications such as those related to gestational diabetes that put both mother and baby at risk during pregnancy.

Insulin resistance occurs when insulin production is normal, yet it fails its purpose – taking glucose into cells where it provides energy. This often leads to the development of type 2 diabetes as the body struggles to stabilize blood sugar levels.

What causes each type of diabetes?

Each type of diabetes has a different cause, even though all of them end with too much glucose in the blood. Type 1 diabetes is caused by the body's own immune system mistakenly attacking and destroying insulin-producing cells in the pancreas. Type 2 diabetes arises from difficulty regulating blood sugar levels due to a combination of factors including genetics, low physical activity and poor nutrition causing insulin resistance. Gestational diabetes happens when insufficient amounts of insulin are produced to keep glucose levels regulated during pregnancy, something which can be attributed either to hormonal imbalances or other medical conditions.

What causes type 1 diabetes?

Type 1 diabetes, an autoimmune disorder, is thought to be the result of a combination of genetic and environmental causes. It occurs when the immune system incorrectly attacks and destroys insulin-producing cells in the pancreas. Common signs indicating this type of condition include increased thirstiness, frequent urination, feeling tired all the time, weight loss and vision troubles.

Management strategies for people with type 1 diabetes involve making modifications such as healthy eating patterns paired with daily exercise, alongside medical treatments like blood sugar monitoring and regular insulin injections. Identifying symptoms early, together with understanding what causes the condition, can help give these individuals access to necessary treatments so they can manage their disease effectively each day.

What causes type 2 diabetes?

Type 2 diabetes is a chronic disorder that affects the way insulin is used by the body and leads to elevated blood sugar levels. This disease has been linked to several factors such as genetics, obesity, lack of physical activity, poor nutrition habits, and certain ethnic groups being more predisposed than others (for example African Americans, Hispanics and Native Americans). To lower their risk level for developing type 2 diabetes, individuals should adopt healthy lifestyle choices while also continuously monitoring their blood sugar levels, along with any necessary medical treatment options. Learn more about the signs of type 2 diabetes.

What causes gestational diabetes?

Gestational diabetes is a form of the condition that some women may experience during pregnancy due to hormonal interference with their body's insulin response. If it isn't properly managed, there can be serious implications for both mother and baby alike. Medical professionals use an oral glucose tolerance test when screening pregnant mothers who might develop gestational diabetes.

Although doctors are still uncertain about what specifically causes this type of diabetes, or even which factors increase risk, taking steps such as maintaining a healthy weight, eating nutritious food and engaging in regular exercise throughout pregnancy can aid in reducing the potential risk of developing this disease – thus resulting in healthier pregnancies all-around.

What are the risk factors for developing diabetes?

The risk factors for diabetes fall into two groups: those you cannot change, such as family history, age, race and ethnicity, and those you can, such as body weight, cholesterol levels, diet and physical activity. Individuals can take proactive steps to better understand their risk of developing diabetes by exploring the various controllable diabetes risk factors. By focusing on the factors that are within one's control – healthy eating habits and a regular exercise routine – it is possible to lower your chance of getting this condition significantly. Knowing about potential risks allows individuals to make informed decisions and develop an appropriate plan for managing any concerns relating to diabetes ahead of time.

Genetic factors

The chances of developing diabetes can be increased if someone has a relative with the condition. Genes found in the HLA region are associated with type 1, while for type 2 there is an established link between family lineage and history. Genes such as HNF1A, HNF1B and HNF4A have been identified as significant contributors to maturity onset diabetes of the young (MODY). Understanding these genetic ties may aid individuals who come from families prone to diabetes in taking measures that could lessen their own risk.

Environmental and lifestyle factors

There are environmental factors which may increase the likelihood of developing diabetes, and these include dietary habits and physical activity levels. To help reduce this risk, individuals should make sure that their diet is filled with nutrient-dense foods such as fruits, vegetables, whole grains and lean proteins. Exercise also plays an important role in controlling blood sugar levels, so people must be consistent when it comes to staying active regularly.

Making conscious choices concerning nutrition and exercise to improve one's overall health can greatly decrease the chance of diabetes complications arising in the long run. Managing a balanced diet along with regular workouts could result positively for an individual's well-being by preventing any progression of high blood sugar related disorders.

Age, race and ethnicity

The risk of developing type 2 diabetes increases with age due to impaired glucose metabolism and insulin resistance. Studies show that certain racial and ethnic groups – African Americans, Hispanics, Native Americans and others – are more likely to develop the condition than Caucasians. Accessibility to healthcare services also plays a role in increasing or decreasing the risk of this illness among different races and ethnicities. Acknowledging all these influencing factors is essential for preventive measures so people can lessen their risk level, or manage diabetic symptoms better if they already have it.

What complications does diabetes cause if it is not controlled?

Uncontrolled diabetes damages blood vessels and nerves, which can bring about severe short- and long-term effects on the body's organs and tissues. Unregulated type 1 diabetes could lead to serious issues, including diabetic ketoacidosis, while women who have gestational diabetes during their pregnancy are at a higher risk of developing type 2 diabetes later in life.

It is essential for those with this condition to understand the potential repercussions associated with it so they can manage their illness well and minimize its impact on overall health and wellbeing. By following a healthy lifestyle combined with frequent monitoring of blood sugar levels, along with appropriate medical treatment when needed, people with diabetes can reduce complication-related risks significantly.

Heart disease and stroke

People with diabetes are more inclined to experience coronary heart disease, heart attacks and strokes than those without the condition. In truth, this occurrence is two to four times higher than in individuals who do not have it. Keeping diabetes under control can help lower the threat of cardiovascular ailments greatly.

In order for people dealing with diabetes to decrease their risk of heart disease effectively, they must stick to a healthy lifestyle, keep track of their blood sugar levels carefully and observe medical advice from health professionals regarding controlling their illness. By taking these necessary steps, individuals affected by diabetes will be able to look after themselves while minimizing potential life-threatening complications.

Kidney and digestive disease

Individuals living with diabetes can lower their odds of developing digestive and kidney ailments by keeping their blood sugar levels stable. This involves following the instructions given to them by healthcare providers in managing their condition well. High glucose concentrations make it more likely for someone to encounter issues such as heartburn or neuropathy, not to mention an increased risk of diabetic nephropathy, due largely to damaged small vessels within the kidneys, which could lead to renal failure if left unattended. Through proper management techniques that regulate a person's glycaemic readings, many of these health problems are avoidable.

Nerve damage (diabetic neuropathy)

Diabetic neuropathy is a type of nerve damage brought on by prolonged exposure to high levels of blood sugar. This can result in damage inflicted on the vessels that provide nourishment to nerves, primarily those located in the extremities. Such damage is likely to cause an array of symptoms like tingling, burning sensations or pain, originating in the toes and fingers before progressing up the body.

To prevent such ill-effects, one must be attentive to monitoring their diabetic condition properly while also keeping elevated blood glucose levels within accepted ranges as advised by their doctor. Taking care of diabetes through observation and being proactive should preserve overall health while avoiding complications caused by poor control.

How can you prevent or manage diabetes?

You can lower your risk of type 2 diabetes, and manage any type of diabetes, by reaching a healthy body weight, eating a balanced diet, staying physically active, monitoring blood sugar and following your treatment plan. Through achieving a healthy body weight, eating an adequately balanced diet and engaging in regular physical activity, you can greatly minimise your risk of type 2 diabetes. Experts advise losing 7% of body mass if aiming to lower the chances further. Read our guide on preventing type 2 diabetes.

Having a wholesome lifestyle plays an important role when trying to stop heart issues too. Along with this, individuals must keep track of their blood sugar levels often and use medical treatments such as pills or insulin shots for effective management of diabetes.

Healthy lifestyle choices

Adopting healthy habits is essential for managing diabetes, as well as avoiding it. Following a balanced diet with plenty of fruits, vegetables, whole grains and lean proteins can help regulate blood sugar levels and contribute to overall wellbeing. Regular physical activity promotes maintaining an ideal weight, decreases stress and assists in controlling glucose concentrations.

To stick with this lifestyle plan, people must also keep up their medical visits regularly, minimize any worry they might have and abstain from smoking, all while staying informed about the consequences these decisions could bring if not followed carefully – by taking responsibility for themselves, individuals will be able to enjoy a higher quality of life despite diabetes.

Regular blood sugar monitoring

Blood sugar monitoring is essential for those managing diabetes and ensuring overall well-being. Using a blood glucose meter, people can check the amount of glucose in their bloodstream and keep track of it over time. Regulating one's blood sugar level helps reduce the risks posed by illnesses connected to diabetes, such as kidney disease, heart problems or nerve damage. Read why you should check your blood sugar.

Failing to monitor levels may produce symptoms like weakness, blurry sight or increased thirst that could lead to more serious consequences if left unchecked. When we stay on top of our readings by routinely tracking them and altering diet and lifestyle accordingly, individuals with this condition are able to remain within acceptable limits.

Medical treatment options

Different medical treatments can be used to manage diabetes, which include oral medications, insulin injections and other injection-based medicines. Oral drugs are employed to keep blood sugar levels in check, while the purpose of insulin shots is regulation of glucose concentration. GLP-1 agonists and SGLT2 inhibitors also help maintain an acceptable blood sugar level. Talk to your doctor about which option is right for you.

By carefully working alongside healthcare professionals and adhering to their tailored treatment plans, individuals with diabetes have a greater opportunity to control their condition while avoiding potential hazards that may arise from leaving it unchecked.

When should you see a doctor about diabetes?

See a doctor if you notice the warning signs of diabetes: excessive thirst, frequent urination, unexplained weight loss, fatigue, blurred vision, recurrent yeast infections, slow-healing sores, or tingling and numbness in the hands or feet. You should also ask for screening if you have a family history of diabetes, are overweight, had gestational diabetes, or belong to a higher-risk ethnic group, even if you feel well, because type 2 diabetes can develop silently for years. A simple diabetes test such as an A1C or fasting glucose can confirm or rule it out. Seek urgent care for severe symptoms such as vomiting, confusion, fruity-smelling breath or rapid breathing, which can signal diabetic ketoacidosis.

Frequently asked questions about what causes diabetes

What are the main causes of diabetes?

Type 2 diabetes is highly connected to sedentary habits, obesity and heredity, and according to the CDC about 90–95% of all US diabetes cases are type 2. Those with specific ethnic origins may be more inclined to develop the illness. Being overweight or having an inactive lifestyle, plus a family background of type 2 diabetes, are known causal elements in many instances of this disease. Type 1 diabetes, by contrast, is caused by an autoimmune attack on the pancreas and is not caused by lifestyle.

Can you get diabetes from eating too much sugar?

Eating sugar does not directly cause diabetes, but a diet high in sugar, processed foods and fried foods contributes to weight gain and insulin resistance, which are major drivers of type 2 diabetes. Type 1 diabetes is not caused by sugar at all. Keeping sugar intake moderate as part of a balanced diet is one of the controllable ways to lower your risk.

How can a healthy person get diabetes?

A person who appears healthy can still develop diabetes because of genetics, age or an autoimmune process they cannot control, and because insulin resistance can build up silently before any symptoms appear. It is essential to maintain a balanced diet and healthy lifestyle in order to protect oneself from developing diabetes or other health issues. Eating foods that are low in sugar, fat, processed items and fried dishes can help reduce visceral fat and lower blood sugar levels even in a person in good health. Having plenty of fruits, vegetables, whole grains and lean proteins in daily meal plans, exercising regularly and getting adequate sleep are also beneficial.

What are the warning signs of diabetes?

Recurrent yeast infections, tingling and numbness in the hands or feet, excessive thirst and frequent urination, and unexplained weight loss can be some of the warning signs that may indicate type 2 diabetes. Fatigue, vision changes and dry skin accompanied by sores which heal slowly are also common indicators. It is important to get tested if you notice any of these signs, because early diagnosis and treatment reduce the risks associated with this disease significantly. Read more about how to know if you have diabetes.

What are the main types of diabetes?

There are three primary forms of diabetes: type 1, type 2 and gestational. Gestational diabetes is a condition affecting pregnant women that may present itself during pregnancy. Prediabetes, where blood sugar is elevated but not yet in the diabetes range, is a warning stage that often precedes type 2 diabetes.

How does insulin resistance contribute to type 2 diabetes?

Insulin resistance is a condition in which the body does not respond as it should to insulin, resulting in higher blood sugar levels and leading to type 2 diabetes. This can cause disruptions of normal metabolism, with too much glucose accumulating in the bloodstream. Over time the pancreas may be unable to produce enough insulin to overcome the resistance.

References, studies and sources

• Mayo Clinic. Diabetes – Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/diabetes/symptoms-causes/syc-20371444
• Centers for Disease Control and Prevention (CDC). Diabetes. https://www.cdc.gov/diabetes/
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Diabetes. https://www.niddk.nih.gov/health-information/diabetes
• American Diabetes Association. About Diabetes. https://diabetes.org/

About the author: Dr. Matthew Capozzi, DPM, FACFAS, CWS, is a board-certified foot surgeon through the American Board of Foot and Ankle Surgery. He is a Diplomate of the American Academy of Wound Management and Fellow of the American College of Foot and Ankle Surgeons. He completed a three-year residency program in Foot and Ankle Reconstructive Surgery at St. Francis Hospital & Medical Center in Hartford, CT in 2010. Dr. Capozzi is a board-certified Wound Specialist® granted by the American Academy of Wound Management.

Healthcare disclaimer: Always consult your physician before beginning any program. This general information is not intended to diagnose any medical condition or to replace your healthcare professional. If you experience any pain or difficulty, stop and consult your healthcare provider. CircuFiber socks are a general wellness product intended to promote a temporary increase in local blood flow and circulation; they are not intended to diagnose, treat, cure, or prevent any disease. Individual results vary.