Pain behind the ankle is most often caused by the Achilles tendon — either tendinopathy in the middle of the tendon or insertional disease where it attaches to the heel. Pain behind the outer ankle bone usually involves the peroneal tendons.
Directly behind the ankle
Achilles tendinopathy causes stiffness and pain in the tendon, often worst in the morning and at the start of exercise.
At the back of the heel
Insertional Achilles tendinopathy, often with a spur or prominent heel bone that rubs in shoes.
Behind the outer ankle bone
Peroneal tendon tendinitis, tears, or tendons snapping out of place, common after ankle sprains.
Behind the inner ankle bone
Posterior tibial tendon problems, which can lead to a collapsing arch.
Urgent sign
A sudden pop with weakness pushing off may be an Achilles rupture and should be seen within days.
From Professional Podiatry Services of New York. General information only; it does not replace an examination.