Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels, resulting from issues with insulin production, insulin action, or both. Insulin is a hormone that regulates how the body uses and stores glucose for energy. When glucose levels remain high over time, it can lead to various additional health problems known as comorbidities or complications. Understanding these associated conditions is important for individuals managing diabetes, as they can significantly affect overall health and quality of life. Proactive awareness allows for better monitoring and timely intervention to mitigate their impact.
How Diabetes Leads to Complications
Sustained high blood sugar (hyperglycemia) drives many diabetes-related health issues. This prolonged elevation of glucose damages blood vessels throughout the body, affecting both large vessels (macrovascular disease) and small vessels (microvascular disease). This damage can lead to widespread physiological changes.
Damage to blood vessels restricts the flow of oxygen and nutrients to various organs and tissues. This can lead to thickening and leaking of small blood vessels and the accumulation of fatty substances in larger ones, contributing to atherosclerosis. Nerve damage (neuropathy) stems from impaired blood supply to nerve fibers. Diabetes is also associated with systemic inflammation and altered lipid metabolism, which further increase the risk of developing these complications.
Heart and Kidney Complications
Cardiovascular diseases are the most frequent and severe complications linked to diabetes, and the leading cause of death for individuals with the condition. High blood sugar levels damage blood vessels, leading to a buildup of fatty plaque (atherosclerosis), which stiffens and narrows arteries. This increases the risk of coronary artery disease, reducing blood flow to the heart and potentially causing angina or a heart attack. People with diabetes are two to four times more likely to develop atherosclerosis and experience related events at a younger age.
Cerebrovascular disease, leading to strokes, is also more common, with mortality from stroke increased almost threefold in individuals with diabetes. Peripheral artery disease (PAD) occurs when blood vessels in the legs narrow, causing pain, especially during walking, and can impair circulation to the feet. Heart failure, a condition where the heart struggles to pump blood effectively, is another significant concern. Diabetes alone can contribute to its development, even without other traditional cardiac risk factors, due to effects like prolonged hyperglycemia and microvascular disease.
Beyond the heart, diabetes impacts kidney function, leading to diabetic nephropathy. This condition arises from persistent high blood glucose levels damaging the small blood vessels and filtering units (nephrons) within the kidneys. A hallmark of diabetic nephropathy is albuminuria, the presence of albumin protein in the urine, which indicates early kidney damage.
As diabetic nephropathy progresses, the kidneys’ ability to filter waste declines, leading to a reduction in glomerular filtration rate. This can advance through five stages, eventually reaching end-stage renal disease (ESRD), where the kidneys no longer function adequately. ESRD often necessitates dialysis or a kidney transplant. Hypertension also contributes to and is a consequence of kidney damage in diabetes, accelerating progression toward kidney failure.
Nerve and Eye Complications
Diabetes-related nerve damage (diabetic neuropathy) affects about half of all individuals with diabetes. This condition results from prolonged high blood glucose levels damaging the small blood vessels that supply nerves. Peripheral neuropathy is the most common form, primarily affecting nerves in the feet and legs, but can also extend to the hands and arms. Symptoms often include numbness, tingling, burning sensations, sharp pains, or heightened sensitivity to touch, which can be worse at night.
Loss of sensation in the feet due to peripheral neuropathy means minor injuries like cuts or blisters may go unnoticed. If ignored, these injuries can progress to serious infections or ulcers, increasing the risk of amputation. Autonomic neuropathy affects the autonomic nervous system, which controls involuntary bodily functions such as heart rate, blood pressure, digestion, and bladder control. This can lead to bladder dysfunction, frequent urinary tract infections, constipation, or diarrhea.
Diabetic retinopathy is an eye complication where high blood sugar levels damage the tiny blood vessels in the retina, the light-sensitive tissue at the back of the eye. These damaged vessels can swell, leak fluid, or become blocked, impairing vision. In advanced stages, abnormal new blood vessels may grow on the retina, which are fragile and can bleed, potentially leading to retinal detachment and severe vision loss or blindness. It is a leading cause of preventable sight loss.
Other eye conditions associated with diabetes include cataracts, which involve clouding of the eye’s natural lens, can lead to blurred vision and may develop at an earlier age in individuals with diabetes. Glaucoma, characterized by increased pressure within the eye that can damage the optic nerve, also has a higher prevalence among those with diabetes. Regular eye examinations are important for early detection and management to preserve vision.
Other Health Complications
Foot problems are a common concern for individuals with diabetes, stemming from nerve damage and poor circulation. Diabetic neuropathy can cause a loss of feeling in the feet, making it difficult to detect cuts, blisters, or sores. Reduced blood flow impairs the healing process, allowing minor injuries to become infected. If these infections do not heal, they can lead to gangrene and, in severe cases, necessitate amputation.
Skin conditions are also more prevalent, including bacterial infections like boils and carbuncles, and fungal infections such as athlete’s foot and ringworm. Dry, itchy skin is common, and scratching can create openings for infection. Specific diabetes-related skin issues include diabetic dermopathy, which causes light brown, scaly patches, and acanthosis nigricans, characterized by darkened, velvety skin in folds like the neck or armpits. Diabetic blisters, resembling burn blisters, can also appear on the hands, feet, or limbs, though they are often painless and heal without scarring if blood glucose is controlled.
Oral health is affected, with an increased risk of gum disease (periodontal disease) and tooth loss. High blood sugar can promote bacterial growth and inflammation in the gums, leading to more severe infections. Mental health conditions, including depression and anxiety, are also common among people living with diabetes, with individuals experiencing up to a twofold increased risk compared to the general population.
Individuals with diabetes also have an increased susceptibility to infections, including urinary tract infections and pneumonia, due to impaired immune function. Sleep apnea, where breathing repeatedly stops and starts during sleep, is observed in people with type 2 diabetes and can worsen blood glucose control.
Strategies for Management and Prevention
Proactive management and ongoing care are important for preventing or delaying diabetes comorbidities. Maintaining strict blood sugar control is foundational, with healthcare providers often recommending specific HbA1c targets, which measure average blood glucose levels over two to three months. Regular monitoring of blood glucose provides insight into how diet and activity affect levels, allowing for adjustments.
Managing blood pressure and cholesterol levels is equally important. High levels of “bad” LDL cholesterol and triglycerides, along with elevated blood pressure, significantly increase the risk of cardiovascular and kidney complications. Medications may be prescribed to achieve target levels for blood glucose, blood pressure, and cholesterol, and adherence to these regimens is important even when feeling well.
Lifestyle interventions form a cornerstone of diabetes management. Adopting a healthy diet, rich in fruits, vegetables, and whole grains, while limiting refined carbohydrates and unhealthy fats, helps regulate blood sugar and weight. Regular physical activity, aiming for at least 150 minutes of moderate-intensity exercise per week, can improve blood glucose, blood pressure, and cholesterol levels. Weight management, including losing even a modest amount of weight if overweight, can substantially reduce the risk of type 2 diabetes progression and its complications.
Regular medical screenings are also a preventative measure. This includes annual dilated eye exams to detect early signs of retinopathy, routine foot exams to check for nerve damage or skin integrity issues, and kidney function tests, often involving urine tests for albumin, to identify early kidney damage. These comprehensive strategies, in collaboration with a healthcare team, can significantly reduce the burden of diabetes-related health problems.