High blood sugar slowly damages your feet: Causes, symptoms and science behind diabetic foot ulcers |

Diabetic foot is one of the most serious and yet preventable complications of diabetes mellitus. It develops when prolonged high blood sugar levels damage the nerves and restrict blood flow, making the feet vulnerable to infections and ulcers. If left untreated, these ulcers can worsen and lead to gangrene or even amputation.Diabetes is rising at an alarming rate across the world, affecting millions each year. While the condition may appear manageable through medication and dietary control, persistent high blood sugar causes silent but progressive damage to the body’s blood vessels and nerves. Over time, this damage compromises circulation, delays wound healing, and weakens the immune system. These combined effects make people with diabetes especially vulnerable to developing foot ulcers and infections that can rapidly become serious if not detected early.

Understanding diabetic foot and causes

A diabetic foot is characterised by infection, ulceration, or tissue destruction in the feet of people with uncontrolled diabetes. This complication arises from a combination of neuropathy (nerve damage), reduced blood circulation, and bacterial infection. Because sensation in the feet is often reduced, small injuries may go unnoticed and untreated, eventually developing into chronic wounds. In severe cases, these ulcers can turn gangrenous, posing a significant risk of amputation or life-threatening infection.The development of diabetic foot involves three major factors: nerve damage, poor circulation, and infection. Neuropathy dulls the ability to feel pain, meaning cuts, blisters, or pressure sores may not be detected in time. Simultaneously, restricted blood flow due to vascular disease prevents oxygen and nutrients from reaching tissues, delaying healing. The warm, moist environment around ulcers becomes a breeding ground for bacteria, which worsens the infection and leads to further tissue damage.The PubMed study review emphasises that diabetic foot ulceration is a devastating complication of diabetes, closely linked to infection, amputation and mortality. It highlights how nerve damage, impaired circulation and foot deformities contribute to ulcer development and delayed healing. The authors stress that careful classification, risk-factor identification and multidisciplinary management are essential to improving outcomes for patients.

Hidden dangers of untreated foot infections in diabetes

Infection plays a central role in the worsening of diabetic foot ulcers. Once bacteria enter an open wound, they multiply rapidly, causing inflammation and tissue necrosis, the death of cells due to lack of oxygen and nutrients. Without timely medical care, the infection spreads deeper into muscles and bones, potentially leading to gangrene. In such cases, surgical removal of the dead tissue or even amputation may become necessary to stop the infection from spreading.Diabetic neuropathy is one of the most common causes of foot ulcers in people with diabetes. It affects the nerves that control sensation in the feet, often making individuals unaware of minor injuries or pressure sores. Repetitive unnoticed injuries can cause cracks, calluses, or ulcers to form. Nerve damage also affects sweat glands, resulting in dry and cracked skin that increases infection risk. Over time, the foot may develop deformities that put uneven pressure on certain areas, further promoting ulcer formation.

How poor blood circulation worsens diabetic foot complications

Peripheral arterial disease (PAD) frequently coexists with diabetes and is caused by a buildup of fatty deposits (atherosclerosis) in the arteries. This leads to poor blood flow and oxygen deprivation in the lower limbs. Even small cuts or bruises can take weeks to heal. In advanced cases, circulation becomes so limited that tissues begin to die, turning black, a sign of gangrene. Detecting PAD early through screening and managing it with medication, exercise, and dietary changes can significantly reduce the risk of severe complications.People with diabetes have a weakened immune response due to persistently high blood sugar levels, making infections more frequent and severe. Elevated glucose levels also encourage bacterial growth, particularly by organisms like Staphylococcus aureus, Streptococcus, and Gram-negative bacteria. Common infections include cellulitis (skin infection), abscesses, and osteomyelitis (bone infection). Prompt medical attention, proper wound cleaning, and antibiotics are essential to control infection before it spreads deeper.

Diabetic foot common symptoms and warning signs

Early recognition of diabetic foot is vital for preventing severe complications. Common signs include:

Since nerve damage can mask pain, people with diabetes should check their feet daily for any visible changes.

Preventing diabetic foot: Practical steps for protection

The best way to prevent diabetic foot is through consistent blood sugar control and meticulous foot care. Preventive measures include:

Lifestyle habits such as maintaining a balanced diet, quitting smoking, and staying active also help improve circulation and overall foot health.Diagnosis and clinical evaluation of diabetic footA comprehensive medical assessment helps determine the severity and underlying cause of a diabetic foot. Doctors look for ulcers, deformities, calluses, and signs of infection. Reduced or absent pulses in the foot suggest poor blood circulation. Diagnostic tests such as blood glucose, HbA1c, and Doppler ultrasound assess metabolic control and blood flow. In cases of infection, a wound swab culture helps identify the bacteria responsible, allowing targeted antibiotic therapy.Also Read | 7 heart diseases caused by high blood pressure you should never ignore