In my guide to type 2 diabetes management, I described diabetic neuropathy as one of the most significant and most preventable complications of poorly controlled blood glucose. I want to expand that section here because neuropathy is one of the conditions in my practice where the gap between what patients understand and what is actually happening in their nervous system creates the most avoidable harm. The numbness that many patients dismiss as normal ageing, the tingling they attribute to sitting in an uncomfortable position, the burning at night they ascribe to heat are all, in many cases, the earliest symptoms of a process that, left unrecognised and unmanaged, can progress to foot ulcers and amputation. Diabetic neuropathy is not an inevitable consequence of diabetes; it is a consequence of uncontrolled diabetes, and that distinction matters enormously.
How Diabetes Damages the Nerves
The mechanism by which chronically elevated blood glucose damages peripheral nerves is well established. Sustained hyperglycaemia produces oxidative stress within nerve cells, impairs the blood supply to the tiny vessels that nourish the nerve fibres (the vasa nervorum), activates inflammatory pathways within the nerve itself, and interferes with the metabolic processes that maintain myelin, the protective sheath around nerve fibres. The cumulative effect is a gradual loss of nerve function, beginning with the longest nerves in the body, which is why the feet and lower legs are affected first. The sensory fibres that carry pain, temperature, and vibration signals are typically affected before the motor fibres that control muscle movement, which is why numbness and tingling precede weakness. The tragedy of diabetic peripheral neuropathy is that the nerve damage that causes numbness also removes the pain signal that would normally alert a person to a foot injury, creating the very conditions in which a wound can develop undetected.
Symptoms: What Diabetic Neuropathy Feels Like
Diabetic neuropathy most commonly presents as a symmetrical, length-dependent pattern of sensory symptoms starting in both feet and gradually progressing upward toward the lower legs. The classic description is a stocking distribution of symptoms. In the early stages, patients may notice tingling, pins and needles, or a sensation of electric shocks in the feet. As damage progresses, there may be burning pain that is typically worse at night and can be severe enough to interfere with sleep. Some patients experience hypersensitivity, where even the touch of a bedsheet is uncomfortable, while others experience the opposite: progressive numbness where sensation is diminished or absent entirely. This numbness is the most dangerous stage, not because it causes more pain but because it eliminates the body's warning system for foot injury entirely.
It is important to recognise that not all neuropathy is symptomatic. Many patients with significant nerve damage on testing have few or no symptoms, because the nerve damage has progressed to a point where there are too few functioning nerve fibres left to generate the tingling or burning that characterises earlier stages. A patient who tells me their feet have stopped hurting after a period of burning pain has not improved. They may have worsened, losing the remaining sensory fibres that produced the pain. The absence of foot symptoms in a long-standing diabetic patient is not reassurance; it is an indication for thorough neuropathy assessment.
From Neuropathy to Foot Ulcer: The Chain of Events
The path from diabetic neuropathy to a serious foot complication follows a predictable sequence that can be interrupted at multiple points when it is identified early. Neuropathy removes the protective pain signal. A small injury, a blister from a tight shoe, a crack in the dry skin of the heel, a cut from walking barefoot, occurs without the patient noticing. Because diabetic peripheral arterial disease also impairs blood supply to the foot in many patients, the wound heals poorly or does not heal at all. Bacteria enter the wound, infection develops, and in a foot with compromised blood supply and absent sensation, infection spreads into deeper tissues. The outcome in many cases that reach hospital late is partial or complete amputation of the foot.
This sequence is not inevitable. It is interrupted by a combination of good glycaemic control to slow nerve damage progression, regular foot examination by the patient and at every diabetes review, prompt attention to any foot wound no matter how minor it appears, appropriate footwear that does not create pressure points, and referral to a vascular surgeon when reduced blood supply is suspected. At Chirayu Multispeciality Clinic, Kasturi Nagar, Bengaluru, a foot examination is part of every diabetes consultation, not a separate appointment, because diabetic foot disease is the complication where early clinical detection makes the greatest difference to outcome.
To book a diabetes consultation with Dr. Santosh Kumar PK at Chirayu Multispeciality Clinic, Kasturi Nagar, Bengaluru, call +91 9164442266.
Written by Dr. Santosh Kumar PK, MBBS (Karnataka University), Master's in Diabetes Management (Middlesex University, London), PGD Clinical Cardiology (Royal College of Physicians, UK), PGD Endocrinology and Clinical Diabetology (Royal College of Physicians, UK), Consultant Physician and Cardio-Diabetologist, Chirayu Multispeciality Clinic, Kasturi Nagar, Bengaluru. 24 years. 25,000 patients. Phone: +91 9164442266.
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