What causes leg pain from the coccyx to the toes?

Leg Pain from Tailbone to Toes: Differential Diagnosis and Management

Most Likely Diagnosis

Your leg pain radiating from the tailbone (coccyx) to the toes most likely represents lumbar radiculopathy (L5-S1 nerve root compression), which requires immediate subspecialist evaluation including electromyography, nerve conduction studies, and MRI. 1

Critical Diagnostic Considerations

The pattern of pain starting at the tailbone and extending to the toes strongly suggests a neurologic origin rather than vascular claudication or isolated musculoskeletal pathology. This distribution is characteristic of nerve root compression affecting the lower lumbar spine. 1

Key Distinguishing Features to Assess

Neurologic symptoms:

• Burning, tingling, numbness, or sharp lancinating pain radiating down the leg suggests nerve root compression rather than vascular or musculoskeletal causes. 2
• Pain that is present at rest and worsens with sitting or standing points toward spinal stenosis or nerve root compression, not vascular claudication which improves with rest. 2
• Relief with lumbar spine flexion is characteristic of spinal stenosis. 2

Vascular claudication (less likely given your symptom pattern):

• Would present as aching, cramping, or fatigue in specific muscle groups (buttock, thigh, calf) triggered consistently by walking a specific distance and relieved within 10 minutes of rest. 2
• Iliac artery occlusive disease can produce hip, buttock, and thigh pain extending to the calf, but this is exercise-induced and rest-relieved. 2

Immediate Diagnostic Algorithm

Step 1: Physical Examination

• Straight leg raise test to assess for radiculopathy. 1
• Neurologic examination checking for motor weakness, sensory deficits, and reflex changes in the lower extremities. 1
• Palpation of lower extremity pulses (femoral, popliteal, posterior tibial, dorsalis pedis) to rule out vascular disease. 2
• Lumbar spine examination for tenderness, range of motion limitations. 1

Step 2: Initial Imaging

• Lumbar spine MRI is the preferred initial imaging if radiculopathy is suspected based on examination findings. 1
• Weight-bearing radiographs of the foot and ankle if localized heel pathology is also suspected. 1

Step 3: Advanced Testing

• Electromyography and nerve conduction studies for confirmed neurologic involvement. 1
• Ankle-brachial index (ABI) measurement if vascular claudication remains in the differential despite atypical presentation. 2

When to Seek Immediate Specialist Referral

You need immediate subspecialist referral for:

• Neurologic heel or leg pain with radiation patterns suggesting nerve involvement. 1
• Any progressive motor weakness or bowel/bladder dysfunction (cauda equina syndrome). 1
• Symptoms suggesting systemic causes when bilateral, involving other joints, or unexplained by mechanical causes. 1

Common Pitfalls to Avoid

Do not assume isolated plantar fasciitis or simple musculoskeletal pain when pain radiates proximally from the heel beyond the local area—this pattern demands neurologic evaluation. 1

Do not diagnose based on imaging alone—you must combine symptoms, clinical signs, and imaging findings. 1

Do not overlook vascular causes entirely: While less likely given your symptom pattern, peripheral arterial disease can present with buttock and thigh pain extending to the calf, particularly if iliac artery disease is present. However, this would be exercise-induced and rest-relieved, not constant or position-dependent. 2

Alternative Diagnoses to Consider

Spinal stenosis: Bilateral buttocks and posterior leg pain that worsens with standing and extending the spine, improves with lumbar flexion, and may take a long time to recover after walking. 2

Severe venous obstructive disease: Entire leg pain with a tight, bursting quality after walking, subsides slowly, relieved by leg elevation, often with history of deep vein thrombosis and visible edema. 2

Hip arthritis: Lateral hip and thigh aching discomfort after variable exercise, not quickly relieved by rest, improved when not bearing weight. 2

Treatment Approach

Treatment cannot be recommended until the underlying diagnosis is confirmed through appropriate neurologic evaluation and imaging. The management differs dramatically between radiculopathy (requiring potential surgical decompression, epidural injections, or physical therapy), vascular disease (requiring risk factor modification, antiplatelet therapy, and possible revascularization), and musculoskeletal causes (requiring conservative management with NSAIDs, physical therapy, and activity modification). 2, 1