Leg Pain: Types, Causes and When It Is Serious

Types of leg pain and what they suggest

The way leg pain feels and when it starts are often the quickest guide to the cause.

Onset of leg pain: sudden vs gradual

Sudden leg pain usually means injury (a pulled hamstring, a torn calf muscle that feels like being kicked, a fracture), a cramp, or less commonly a blood clot or a blocked artery. Gradual leg pain over weeks suggests overuse, arthritis, nerve problems or narrowing arteries. Pain that wakes you at night and is not relieved by rest, or comes with weight loss or fever, needs investigation for infection or, rarely, a bone tumor.

Common causes of leg pain

Muscle strain and cramps

Overstretching or tearing muscle fibers causes pain, bruising and weakness, most often in the hamstrings, calf and groin. Leg cramps are sudden, painful tightening of a muscle, usually the calf, often at night. They are common in older adults, during pregnancy, after hard exercise and with medicines such as diuretics and statins.

Overuse injuries

• Shin splints: aching along the inner edge of the shin in runners and people who suddenly increase training.
• Stress fractures: a tiny crack in the bone, causing pinpoint pain that worsens with each run.
• Tendinitis: pain at the Achilles tendon, the knee (patellar tendon) or around the hip.

Joint problems

Knee and hip osteoarthritis cause pain that can be felt in the thigh, groin or shin. Gout causes a sudden hot, swollen joint. See knee pain for more on knee causes.

Sciatica and spinal stenosis

A bulging disc or narrowed spinal canal can press on a nerve root in the lower back. Sciatica causes pain running from the buttock down the back or side of the leg, often below the knee, with tingling and sometimes weakness. Spinal stenosis causes aching or heaviness in both legs on standing and walking, relieved by sitting or bending forward.

Serious causes not to miss

Deep vein thrombosis (DVT)

A clot in a deep vein, usually of the calf or thigh, causes swelling of one leg, aching or cramping pain, warmth and redness. Risk factors include recent surgery, long flights, pregnancy, hormone pills, cancer and a previous clot. A deep vein thrombosis can travel to the lungs, so it needs same-day assessment.

Peripheral artery disease (PAD)

Narrowed arteries reduce blood flow to the legs. The classic symptom is claudication: calf, thigh or buttock pain that comes on after walking a set distance and goes within minutes of rest. Severe peripheral artery disease causes pain at rest, especially at night, and sores that do not heal. Smoking and diabetes are the main risks.

Acute limb ischemia

A sudden blockage of an artery, from a clot or an embolus from the heart, causes the "six Ps": pain, pallor, pulselessness, pins and needles, paralysis and a cold leg. This is a surgical emergency.

Cellulitis

A bacterial skin infection causing a spreading, hot, red, swollen and tender area, often with fever. Cellulitis needs antibiotics.

Compartment syndrome

Rising pressure inside a muscle compartment, usually after a fracture or crush injury, causing severe, escalating pain. It needs emergency surgery.

Leg pain with a lump

A soft, painless, movable lump is often a lipoma. A lump behind the knee may be a Baker's cyst, which can burst and cause calf pain and swelling that looks like a clot. A tender lump on the inside of the lower leg along a vein can be superficial thrombophlebitis, an inflamed vein with a clot, which is usually treated with warmth, anti-inflammatory medicine and support but sometimes needs an ultrasound. A hard, growing or deep lump, or one larger than 5 cm, should be checked to rule out a soft tissue tumor.

How doctors diagnose leg pain

A doctor will ask exactly where the pain is, how it started, what makes it worse, and about walking distance, swelling, numbness, back pain and risk factors. They examine the leg, check pulses, skin, swelling, joint movement, strength and reflexes. Tests depend on the suspected cause:

• Duplex ultrasound of the veins for DVT, or the arteries for PAD
• D-dimer blood test to help rule out a clot
• Ankle-brachial index: comparing blood pressure at the ankle and arm to detect PAD
• X-rays, MRI or bone scan for fractures and stress fractures
• MRI of the spine for sciatica with weakness or persistent symptoms
• Blood tests for infection, blood sugar, kidney function, vitamin B12 and thyroid
• Nerve conduction studies for neuropathy

Treatment and home care

For muscle and overuse pain

• Rest from the aggravating activity for a few days, then return gradually.
• Ice wrapped in a cloth for 15 to 20 minutes, several times a day for the first 48 hours, then heat for stiffness.
• Gentle stretching, especially of the calves and hamstrings.
• Acetaminophen (paracetamol) or an NSAID such as ibuprofen, following the label dose. Avoid NSAIDs if you have kidney disease, stomach ulcers or take blood thinners, unless your doctor agrees.
• Supportive footwear and a gradual training program.

For cramps

Stretch the muscle by pulling the toes toward you, massage it, and walk it off. Stretching the calves before bed can reduce night cramps. Ask your doctor to review medicines if cramps are frequent.

Treating specific causes

• DVT: blood thinners for at least 3 months.
• PAD: supervised walking exercise, stopping smoking, statins and antiplatelet medicine, and sometimes angioplasty or bypass surgery.
• Sciatica: staying active, physical therapy and pain relief; most cases settle within 6 to 12 weeks.
• Neuropathy: controlling the cause, foot care, and medicines for nerve pain.
• Cellulitis: antibiotics and raising the leg.

Frequently asked questions

What are the different types of leg pain?

Leg pain is usually grouped by source: muscle (aches, strains, cramps), bone (stress fractures), joint (arthritis), nerve (sciatica, neuropathy), vein (clots, varicose veins), artery (claudication) and skin infection (cellulitis). Each feels different, which helps doctors narrow down the cause.

When is leg pain serious?

Leg pain is serious when it comes with swelling and warmth in one calf, a cold pale or numb leg, inability to bear weight, a hot spreading red area with fever, or breathlessness. These can signal a clot, a blocked artery, a fracture or infection, and need urgent care.

How can I tell if leg pain is a blood clot?

A clot usually affects one leg, causing swelling, a heavy ache or cramp in the calf or thigh, warmth and redness. It often follows surgery, travel, pregnancy or illness. You cannot reliably tell at home, so get same-day assessment. An ultrasound confirms or rules it out.

Why do my legs hurt when I walk?

Pain that comes on after walking a set distance and eases within minutes of standing still is typical of peripheral artery disease. Pain eased only by sitting or bending forward suggests spinal stenosis. Pain on every step at one bony spot suggests a stress fracture. See a doctor for testing.

Why do my legs hurt at night?

Night leg pain is most often from cramps or restless legs syndrome. It can also come from arthritis, nerve problems or, in children, growing pains. Severe pain at rest in the feet, eased by hanging the leg over the bed, can mean advanced artery disease.