Achilles tendinopathy can cause pain, inflammation and stiffness of the Achilles tendon at the back of the ankle. It can occur as an over-use injury in people who take part in excessive exercise or exercise they're not used to. For example, it can affect marathon runners. It can also affect people who have reactive arthritis or ankylosing spondylitis.
Read more about achilles tendinopathy in our foot and ankle pain section.