The definition of adult flatfoot is self-explanatory. It can be summed up in its name—flat feet that occur in adulthood. However, while the name is decipherable, the methods for treating its painful symptoms may be a bit more unclear to you. Let the experts at Achilles Foot and Ankle explain.

Adult flatfoot happens when your arch collapses, causing your feet to point outward. In fact, if you have someone take a look at your feet from behind you, they’ll likely be able to see all your toes from the back. Besides these visible signs, pain is the main symptom. The inside of your foot will feel it, and your ankle will too. The outside part of the ankle may hurt as well, because the collapse of the arch puts more pressure on the outside of your foot.

With this condition, high-impact activities are going to be very painful. You might not even be able to walk or stand up without discomfort. People with arthritis may notice that they aren’t able to wear their shoes, due to bumps on the top and inside of their foot. Diabetics need to watch out, because they might not feel pain at all. Instead, a swollen lump will form on the bottom of their arch.

Obesity, occupation, shoes, and your activity level could be some factors creating your problem. Posterior tibial tendon dysfunction (PTTD), damage to the tendon that holds up your arch, is the most common cause. The tendon becomes inflamed and torn with repeated overuse, which means it no longer has the strength to support the arch. Over time, the arch collapses. People who play high-impact sports like soccer, basketball, or tennis can also develop this condition.

Sometimes the condition is hereditary, since a foot type prone to collapse can be passed down from one generation to the next. Conditions like diabetes and rheumatoid arthritis also associate with this, and may increase your chances of developing a poor foot structure. A ligament injury in the foot is another incident that can break the support needed to hold up your arch.