When you experience ankle or foot pain, it’s probably tempting to dismiss it as “just a mild sprain” or “only a pulled muscle.” The truth is usually more complicated than that. The bottom line is that if you have ankle or foot pain lasting more than a couple of days, it’s time to seek treatment.

It’s particularly important to get treatment if you’re experiencing additional problems like ankle instability or weakness, foot or ankle numbness, or tingling sensations. These problems can indicate underlying nerve damage or other serious issues that require a doctor’s attention.

Some of the many reasons for foot and ankle pain include:

Tarsal tunnel syndrome

Tarsal tunnel syndrome is nerve entrapment involving your posterior or anterior tibial nerves. Both forms of this condition can cause foot pain and symptoms like numbness and tingling. Posterior tarsal tunnel syndrome causes symptoms in the sole of the foot. Anterior tarsal tunnel syndrome causes symptoms in the top of your foot and in your big and second toes.

Morton’s neuroma

Morton’s neuroma is nerve entrapment involving one of the plantar nerves at the top of your foot. It can feel like having a pebble stuck under the ball of your foot.

Osteoarthritis

Osteoarthritis is the most common form of arthritis. It attacks the cartilage covering the ends of the bones that make up your joints. The cartilage wears down gradually, which eventually causes bone to rub against bone, leading to foot or ankle pain.

Nerve problems

The posterior and anterior tibial nerves, both branches of the sciatic nerve that runs down your buttocks and legs, can cause ankle and foot pain. Irritation of the primary nerves in your calf, the bottom of your leg, and in your knee can also cause foot and ankle pain.

Tendon problems

Tendon problems show up in the peroneal, anterior tibialis, and Achilles tendons. Problems range from inflammation to partial or complete tears, both of which can cause severe foot or ankle pain.

Ligament problems

Ligaments can stretch or tear, causing sprains and severe foot and ankle pain. Ankle sprains are the most common sprains. Plantar fasciitis develops when the thick ligament on the bottom of your foot suffers small tears, causing heel pain.

In some cases, one foot or ankle problem can lead to another. For example, a sprain causes not only pain but weakness and instability. This can leave you vulnerable to a bone fracture and other complications.