What are the causes and treatments for numbness and tingling in the hands and feet?

Evaluation and Management of Numbness and Tingling in Hands and Feet

Start by screening for diabetes with fasting glucose and HbA1c, as diabetic peripheral neuropathy is the most common cause of bilateral hand and foot numbness and tingling, and optimizing glucose control is the only proven disease-modifying intervention. 1, 2

Initial Clinical Assessment

Determine the distribution pattern immediately:

• Distal symmetric (stocking-glove) suggests metabolic or toxic causes like diabetes, vitamin B12 deficiency, or medication toxicity 2
• Patchy or asymmetric suggests mononeuropathy multiplex from vasculitis or multiple nerve entrapments 2
• Unilateral hand symptoms point to carpal tunnel syndrome, the most common nerve entrapment 3, 4

Characterize fiber type involvement:

• Small fiber symptoms: burning pain, tingling, temperature sensitivity, worse at night 2, 5
• Large fiber symptoms: numbness with loss of balance, vibration loss 2

Critical red flags requiring urgent evaluation:

• Acute onset (within days) or rapidly progressive symptoms may indicate Guillain-Barré syndrome 3
• Asymmetric presentation with motor weakness suggests vasculitis 3
• Severe dysautonomia (orthostatic hypotension, gastroparesis) 1

Physical Examination

Perform these specific tests:

• 10-g monofilament testing at multiple plantar sites to assess protective sensation 1, 5
• 128-Hz tuning fork for vibration testing at toes and fingers 2, 5
• Pinprick and temperature sensation for small fiber function 2, 5
• Ankle reflexes for large fiber assessment 2, 5
• Durkan maneuver (firm digital pressure across carpal tunnel) if unilateral hand symptoms—64% sensitive, 83% specific for carpal tunnel syndrome 4
• Tinel's and Phalen's signs for carpal tunnel syndrome 6

Laboratory Workup

Order these tests in sequence:

First-line (order immediately):

• Fasting glucose and HbA1c—diabetes causes up to 50% of peripheral neuropathy cases 1, 5
• Vitamin B12 level—deficiency causes sensory neuropathy, especially critical in metformin users 1, 2
• Complete blood count—screens for anemia, infection, malignancy 2
• Comprehensive metabolic panel—assesses renal function and electrolytes 5
• Thyroid function tests (TSH, free T4)—hypothyroidism causes neuropathy 5

Second-line (if first-line negative):

• Hepatitis C serology if risk factors present—up to 50% of HCV patients develop neuropathy 2
• Hepatitis B and HIV testing if clinically indicated 1

Avoid routine imaging—it is low-yield unless red flags present (trauma, inability to bear weight, point tenderness over bone) 5

Reserve electrodiagnostic testing (EMG/NCS) for atypical presentations or when diagnosis remains unclear after 6-8 weeks, as clinical history is usually sufficient 7, 5

Treatment Algorithm

If Diabetic Neuropathy Confirmed:

Disease-modifying therapy:

• Optimize glucose control to HbA1c 6-7%—this is the ONLY proven strategy to prevent or delay progression 1, 2
• Address hypertension and hyperlipidemia aggressively 1

Symptomatic pain management (if painful neuropathy present):

• First-line: Duloxetine 60 mg once daily, increase to 120 mg if needed 7, 1, 2
• Alternative first-line: Pregabalin 150-300 mg/day in divided doses 1, 2, 8
• Alternative first-line: Gabapentin (dose titration required) 1, 2
• Second-line: Tricyclic antidepressants (amitriptyline 25-75 mg/day)—effective but significant anticholinergic side effects 1, 2
• Topical options: Capsaicin 8% patch or 0.075% cream 2

Critical pitfall: Do NOT use opioids (tapentadol, tramadol) for chronic neuropathic pain due to addiction risk 2

If Vitamin B12 Deficiency:

• Supplement with 2500 mcg daily, particularly in metformin users 2
• Monitor metformin users closely—long-term use causes B12 deficiency and stocking-glove neuropathy 2

If Chemotherapy-Induced Peripheral Neuropathy (CIPN):

During active chemotherapy:

• Discuss dose delay, dose reduction, or stopping chemotherapy with oncologist if intolerable neuropathy or functional impairment develops 7
• Do NOT use acetyl-L-carnitine—harms outweigh benefits 2
• Exercise therapy shows preliminary benefit but needs larger studies for definitive recommendation 7

After chemotherapy completion:

• Duloxetine is the ONLY agent with appropriate evidence for painful CIPN, though benefit is limited 7, 1
• Physical activity improves neuropathic pain and should be offered to all patients 7, 1
• No recommendation can be made for gabapentin/pregabalin, acupuncture, or scrambler therapy outside clinical trials 7

If Carpal Tunnel Syndrome (unilateral hand symptoms):

• First-line: Wrist splinting or steroid injection for temporary relief 4
• Definitive treatment: Open or endoscopic carpal tunnel release for patients unresponsive to conservative therapy 4
• Electrodiagnostic testing is >80% sensitive and 95% specific if diagnosis uncertain 4

Non-Pharmacological Interventions (All Causes)

• Regular physical activity for both diabetic and chemotherapy-induced neuropathy 7, 1, 2
• Acupuncture may be offered for musculoskeletal-related neuropathic symptoms 2
• Cognitive behavioral therapy for pain management 1

Monitoring and Follow-up

Risk-stratified screening intervals for diabetic patients:

• Every 6-12 months if loss of protective sensation (LOPS) or peripheral arterial disease (PAD) alone 5
• Every 3-6 months if LOPS + PAD, or either with foot deformity/callus 5
• Every 1-3 months if history of ulcer/amputation or end-stage renal disease 5

Annual screening recommended:

• All type 2 diabetes patients 1
• Type 1 diabetes patients after 5 years 1

Assess for complications:

• Autonomic neuropathy (orthostatic hypotension, gastroparesis) 1
• Foot ulcers—perform annual 10-g monofilament testing once LOPS documented 2, 5

Common Pitfalls to Avoid

• Do not assume symptoms are purely mechanical without screening for diabetes, even in young adults 5
• Do not order extensive imaging initially—this is a clinical diagnosis 5
• Do not use opioids for chronic neuropathic pain 2
• Do not use acetyl-L-carnitine for CIPN prevention 2
• Start medications at lower doses in older patients and titrate slowly to minimize adverse events (dizziness, somnolence are common with pregabalin and duloxetine) 2, 8
• Monitor for pregabalin side effects: dizziness (21-32%), somnolence (12-22%), peripheral edema (9%), weight gain (4-12%), and confusion (2-4%) are dose-dependent 8