How Diabetes Affects the Body

Diabetes is a condition that affects the way the body uses glucose. Glucose is the main source of energy for the body and comes from the food that we eat. Diabetes is caused by having too much sugar, in the form of glucose, circulating in the blood. These high levels of blood sugar happen because the cells become insulin resistant. This means that they cannot take in the glucose that they need. Over time, high levels of sugar can damage your heart, blood vessels, eyes, nerves, and kidneys.

There are two types of diabetes: type 1 and type 2. Type 1 diabetes is classified as an autoimmune disease, where the pancreas no longer produces insulin. Insulin is necessary to help the body use glucose for energy. There is no cure for type 1 diabetes. Type 2 diabetes is the most common form of the disease and is caused by poor diet and lifestyle choices.

Diabetes can cause a variety of complications, including heart disease, stroke, blindness, kidney failure, and amputations. It’s important to understand how diabetes affects different parts of the body so that you can take steps to prevent, or delay, these complications.

How does diabetes affect the heart?

Diabetes can take a serious toll on your heart and is one of the leading causes of heart disease. Diabetics are at risk of developing heart disease at a much earlier age than non-diabetic people. In addition, having diabetes makes you more likely to develop problems with your heart. High blood sugar damages the arteries that supply blood to the heart, making them more vulnerable to plaque build up and blockages.

This can lead to a heart attack or stroke, which could ultimately lead to death! (1)

Another way in which diabetes can affect the body is by causing high blood pressure. This puts extra strain on the heart and can lead to heart failure (2).

Abnormalities in the heart’s electrical system are common in people with diabetes and can lead to irregular heartbeats (3).

The medical term for this is arrhythmia. Arrhythmias are a major risk factor for heart attacks and strokes, both of which can, unfortunately, be fatal. High cholesterol is another issue that can lead to strokes. The bad news is that diabetes is a contributing factor to high cholesterol (4).

So it is important to keep an eye on your cholesterol as well as your blood sugar, get tested regularly, and make sure you are following a healthy diet and taking the necessary medication to keep these life-limiting diseases under control.

Unfortunately, there is more bad news for the heart, as diabetes is also a major cause of heart failure (4).

This means that the heart is not able to pump enough blood to meet the body’s needs. Heart failure can be very debilitating, and can lead to fluid buildup in the legs and lungs. This can make it really hard to breathe and can be fatal if not caught early.

How does diabetes affect the brain?

Diabetes can have a serious impact on the brain. The brain needs a constant supply of oxygen and nutrients. It gets them via the blood vessels. Diabetes can damage the blood vessels significantly, which will affect the supply of oxygen and nutrients to the brain. Without them, parts of the brain will suffer damage and die. This can have the knock-on effect of causing memory loss, and dementia (5). The brain needs glucose for energy and uses more of it than any other organ in the body (6). Therefore, in the case of low blood sugar, or hypoglycemia, the brain will struggle to function. This is a known complication of type 1 diabetes and can cause us to learn more slowly (7).

Diabetes is a known cause of inflammation (8). The brain is particularly sensitive to this, and the outcome can be cognitive problems, decreased concentration, and memory loss (9).

A large proportion of the brain is made up of nervous tissue (10). Diabetes and high sugar levels can damage the nerves that send signals from the brain to the body. This can cause problems with movement and coordination (11).

Diabetes causes insulin resistance in the liver and muscle cells. When there is insulin resistance in the brain cells, this can lead to dementia, specifically Alzheimer’s disease (12). This is the reason that Alzheimer’s disease is now being referred to as “type 3 diabetes”, in the scientific and medical community (13).

How does diabetes affect the nervous system?

The high blood sugar levels associated with diabetes can cause damage to the nerves that send messages from the brain to the body. This is called diabetic neuropathy and can cause a variety of symptoms, including pain, numbness, tingling, and weakness (14). There are four kinds of diabetic neuropathy. Each type affects different nerves in the body and can cause different symptoms. Peripheral neuropathy affects the nerves in the extremities; the legs, feet, arms, and hands. It causes pain, numbness, tingling, and weakness. It can also cause painful ulcers and infections on the skin.

How does diabetes affect the nervous system?: nervous-system-graphic

Autonomic neuropathy has an adverse effect on the nerves that control automatic functions like blood pressure and heart rate (15). This can cause problems such as irregular heartbeats and blood pressure issues. Autonomic neuropathy also affects the organs inside the body. This can cause bladder and bowel control issues, affect the sex organs, impact sexual performance, and affect the movement of food through the digestive system (11). Finally, autonomic neuropathy can also affect the sensors that sense low blood sugar. This means the diabetic is not aware of the warning signs that they have low blood sugar, which can be dangerous. These people need to wear a continuous blood sugar monitor that sounds an alarm when the blood sugar levels are too low (16).

Proximal neuropathy affects the nerves in the torso. This includes the hips, thighs, stomach, and chest. Proximal neuropathy causes pain, and weakness and can affect mobility (11). The nerves that are most commonly affected by focal nerve damage are individual nerves. Focal nerve damage affects the eyes, and face and can cause double vision, trouble focusing, and also partial paralysis of the side of the face, known as Bell’s Palsy (17).

Diabetic neuropathy is a serious complication of diabetes, so again, it is really important to control your blood sugar levels to help prevent debilitating nerve damage.

How does diabetes affect the eyes?

Diabetes can also cause serious problems with our eyes. Diabetes causes damage to the blood vessels in the cells at the back of the eye that are responsible for processing visual information. These damaged blood vessels can bleed and leak a watery fluid, causing blurred vision. In severe cases, diabetic retinopathy can lead to blindness. Diabetic retinopathy is a leading cause of blindness in adults, and early detection is crucial to preserving vision.

Cataracts are another common eye problem associated with diabetes (18). They occur when the lens of the eye becomes cloudy, making it difficult to see clearly, and are the main cause of blindness. Glaucoma is another disorder that can be caused by diabetes (19). It occurs when the pressure inside the eye increases, damaging the optic nerve. If left untreated, glaucoma can also lead to blindness. It is important for people with diabetes to have regular eye examinations so that any problems can be detected and treated early.


If you have diabetes, it’s important to monitor your blood sugar levels carefully and regularly and take steps to control your diabetes. This includes eating a healthy diet, getting regular exercise, and taking medication as prescribed. It is also important to work with your doctor, diabetic practitioner, and optician to manage your condition effectively. Taking steps to keep yourself healthy is one of the best things you can do for your overall health, and it may help you avoid some serious complications down the road.


Diabetes, Heart Disease, & Stroke

Blood pressure

Diabetes and Arrhythmias: Pathophysiology, Mechanisms and Therapeutic Outcomes

Diabetes and Your Heart

The Effects of Diabetes on the Brain

Why Does the Brain Need So Much Power?

The Effects of Type 1 Diabetes on Cognitive Performance: A meta-analysis

The Role of Inflammation in Diabetes: Current Concepts and Future Perspectives

Impact of diabetes on cognitive function and brain structure

Nervous Tissue

Diabetes and Nerve Damage

Insulin Resistance in Brain and Possible Therapeutic Approaches

Is Alzheimer's disease a Type 3 Diabetes? A critical appraisal

Hyperglycemia Induces Cellular Hypoxia through Production of Mitochondrial ROS Followed by Suppression of Aquaporin-1

Autonomic Neuropathy

Hypoglycemia (Low Blood Glucose)

Diabetic Neuropathy

Cataract in diabetes mellitus

Diabetes Mellitus as a Risk Factor for Open-Angle Glaucoma: A Systematic Review and Meta-Analysis