Plantar fasciitis is a common cause of heel pain, characterized by a sharp, stabbing sensation often most severe with the first steps in the morning or after periods of rest. It involves inflammation of the plantar fascia, a thick band of tissue connecting the heel bone to the toes, which supports the foot’s arch and absorbs shock. Various other conditions can produce similar symptoms, making an accurate diagnosis important for effective treatment.
Nerve Compression and Entrapment
Nerve compression or entrapment within the foot or leg can lead to pain that closely resembles plantar fasciitis. Tarsal tunnel syndrome, for instance, occurs when the posterior tibial nerve, which runs along the inside of the ankle, becomes compressed. This compression can cause burning, tingling, or numbness that radiates into the sole of the foot or heel, much like carpal tunnel syndrome affects the wrist.
Another specific nerve issue is Baxter’s nerve entrapment, involving the first branch of the lateral plantar nerve. This condition is frequently confused with plantar fasciitis. Unlike plantar fasciitis, where pain often improves with initial movement, Baxter’s nerve entrapment pain may worsen with physical activity. Referred pain from the lower back, such as sciatica, can also radiate to the heel, mimicking foot-specific pain. Compression of the S1 nerve root can lead to discomfort, numbness, or tingling that extends down the leg and into the heel.
Bone and Joint-Related Conditions
Bone and joint conditions in the foot and ankle can also cause heel pain. Stress fractures of the calcaneus (heel bone) are tiny cracks from repetitive stress. This pain often intensifies with activity and subsides with rest, and the heel may feel tender or warm to the touch.
Heel spurs are bony growths that can form on the underside of the heel bone, often in response to chronic stress on the plantar fascia. While many heel spurs are painless, they can cause discomfort mistaken for plantar fasciitis. Various forms of arthritis (gout, rheumatoid, psoriatic) can affect foot and ankle joints, including the heel. These conditions can lead to inflammation, stiffness, and pain, particularly in the morning or after periods of inactivity.
Soft Tissue and Structural Issues
Soft tissue and structural issues in the foot can also cause heel pain. Fat pad atrophy is the thinning of the natural fatty cushioning under the heel. This thinning increases pressure on the heel bone, causing deep, bruise-like pain, especially when walking barefoot or on hard surfaces.
Subcalcaneal bursitis is inflammation of a bursa, a fluid-filled sac beneath the heel bone that reduces friction. When irritated, this bursa causes pain and swelling in the heel, mimicking plantar fasciitis. Achilles tendinopathy, inflammation or degeneration of the Achilles tendon, causes pain at the back of the heel where it connects to the bone. While distinct from plantar fasciitis (which affects the sole), the general heel discomfort can lead to confusion.