What is the diagnosis for numbness and tingling in the foot that is relieved by dangling the foot over the side of the bed?

Peripheral Artery Disease (Critical Limb Ischemia)

The diagnosis is peripheral artery disease (PAD) with critical limb ischemia—the relief of foot numbness and tingling by dangling the leg over the bedside is a classic sign of severe arterial insufficiency where gravity improves blood flow to the ischemic foot. 1

Why This Diagnosis is Most Likely

The positional relief pattern is pathognomonic for PAD with critical ischemia:

• Dangling the foot increases perfusion pressure through gravitational assistance, temporarily relieving ischemic rest pain and paresthesias that occur when the limb is elevated (such as lying flat in bed) 1
• This contrasts sharply with diabetic peripheral neuropathy or other neuropathies, where symptoms are not position-dependent and do not improve with dangling 2, 3
• Patients with severe PAD characteristically report that symptoms worsen at night when lying flat and improve when sitting with legs dependent 1

Critical Distinguishing Features from Neuropathy

Peripheral neuropathy does NOT improve with positional changes:

• Diabetic peripheral neuropathy causes constant burning, tingling, and "electrical shock" sensations that are characteristically worse at night but unrelated to leg position 2
• Neuropathic symptoms affect both feet symmetrically in a stocking-glove distribution and progress proximally over time, regardless of body position 3
• The American Diabetes Association confirms that neuropathic pain severity relates to sleep disturbance, not gravitational effects 2

Immediate Diagnostic Workup Required

Measure ankle-brachial index (ABI) and toe pressures urgently:

• ABI <0.9 confirms PAD diagnosis 2
• Toe pressure <30 mmHg or transcutaneous oxygen pressure (TcPO2) <25 mmHg indicates critical limb ischemia requiring urgent vascular imaging and revascularization 2
• Triphasic pedal Doppler arterial waveforms largely exclude significant PAD 2
• Toe-brachial index ≥0.75 makes PAD unlikely 2

Examine pedal pulses and assess for other PAD signs:

• Absent foot pulses, cool lower limb, femoral bruits, and slow venous filling time suggest PAD 2
• Palpable pulses do not exclude significant ischemia—objective testing is mandatory 2

Management Algorithm

If toe pressure <30 mmHg or TcPO2 <25 mmHg:

• Obtain urgent vascular imaging (CT angiography or MR angiography) 2
• Refer immediately to vascular surgery for revascularization consideration 2

If bedside tests show PAD but not critical ischemia:

• Initiate antiplatelet therapy (aspirin or clopidogrel) 2
• Start high-dose statin therapy (atorvastatin 80 mg daily reduces stroke by 33% and major coronary events by 43% in patients with carotid stenosis) 2
• Consider vascular imaging if ulcer fails to improve within 6 weeks despite optimal management 2

Common Pitfalls to Avoid

Do not assume diabetic neuropathy based on diabetes history alone:

• Up to 50% of diabetic patients with foot ulcers have PAD, not just neuropathy 2
• The positional relief pattern is incompatible with pure neuropathy 1
• Diabetic microangiopathy should not be assumed as the cause of poor wound healing—PAD must be excluded 2

Do not rely on clinical examination alone:

• Even skilled examiners can miss significant ischemia when pulses are palpable 2
• Medial arterial calcification (Mönckeberg sclerosis) can falsely elevate ABI ≥1.3, requiring toe pressure measurement instead 2

Recognize that spinal stenosis can mimic this presentation:

• Neurogenic positional pedal neuritis from lumbar spinal stenosis causes foot symptoms relieved by spine flexion (sitting/bending forward), not simple leg dangling 1
• However, spinal stenosis symptoms typically worsen with standing/walking and improve with sitting in a flexed position, distinct from the lying-flat-to-dangling pattern of PAD 1