What are the symptoms of diabetic neuropathy?

Symptoms of Diabetic Neuropathy

Diabetic neuropathy presents with a wide spectrum of symptoms affecting sensory, motor, and autonomic nerve function, with up to 50% of cases being completely asymptomatic, making screening essential even in the absence of complaints. 1

Peripheral Sensory Symptoms (Most Common Presentation)

The most common form is distal symmetric polyneuropathy, which typically begins in the toes and feet with gradual ascending progression:

Positive Sensory Symptoms

• Burning pain in the feet and lower legs, often described as intense and constant 2, 3
• "Electric shock" sensations or shooting pains 2
• Hyperalgesia where normal touch from clothing, socks, or bedsheets causes severe pain 2
• Tingling and "pins and needles" sensations (paresthesias) 4, 3
• Pain that typically worsens at night 3

Negative Sensory Symptoms

• Numbness affecting feet in a "stocking" distribution, later progressing to hands in a "glove" pattern 2, 3
• Loss of sensation to touch, temperature, and pain 3
• Reduced or absent ankle reflexes 5, 3

Critical pitfall: Up to 50% of diabetic peripheral neuropathy is asymptomatic, placing patients at high risk for unrecognized foot injuries, ulcers, and amputations if preventive care is not implemented. 1

Autonomic Nervous System Symptoms

Autonomic neuropathy affects multiple organ systems and should be assessed annually in patients with type 1 diabetes ≥5 years duration and all patients with type 2 diabetes: 1

Cardiovascular Manifestations

• Resting tachycardia (heart rate >100 bpm), often an early sign 6
• Orthostatic hypotension: dizziness, lightheadedness, or weakness upon standing (defined as systolic BP drop >20 mmHg or diastolic drop >10 mmHg without appropriate heart rate increase) 1, 6
• Syncope or near-syncope episodes 1
• Exercise intolerance 1
• Silent myocardial ischemia (chest pain may be absent during heart attacks due to impaired pain perception) 6

Gastrointestinal Symptoms

• Gastroparesis: erratic blood glucose control, early satiety, nausea, vomiting, bloating 1
• Esophageal dysmotility with difficulty swallowing 1
• Constipation or diarrhea (often alternating) 1, 6
• Fecal incontinence 1
• Postprandial hypotension (lightheadedness after meals) 6

Genitourinary Symptoms

• Male sexual dysfunction: erectile dysfunction and/or retrograde ejaculation 1, 6
• Female sexual dysfunction: decreased sexual desire, pain during intercourse, decreased arousal, inadequate lubrication 1, 6
• Bladder dysfunction: urinary incontinence, nocturia, frequent urination, urination urgency, weak urinary stream, urinary retention 1, 6

Sudomotor (Sweating) Dysfunction

• Increased or decreased sweating 1
• Dry, cracked skin in the extremities 6
• Changes in sweat function patterns 1

Motor Symptoms (Less Common)

• Proximal muscle weakness in the thighs and hips, particularly in diabetic proximal motor neuropathy 2
• Gait disturbances and increased fall risk in advanced cases 3
• Muscle wasting in severe cases 3

Clinical Presentation Patterns

Bilateral and symmetric involvement is the hallmark of typical diabetic neuropathy, starting distally and progressing proximally. 5, 3 Asymmetric presentations should prompt consideration of alternative diagnoses or additional electrophysiological testing. 3

Recognition and treatment of autonomic neuropathy may improve symptoms, reduce complications, and improve quality of life, making systematic screening for these diverse symptoms essential in all patients with diabetes. 1, 6