Flatfoot occurs when the arch of the foot collapses, causing the foot to flatten against the ground. This can lead to pain, swelling, and discomfort in the foot, particularly after prolonged standing or walking. Over time, flatfoot can cause strain on the ankles, knees, and lower back due to improper weight distribution. The condition can be congenital or develop from injury or overuse. In more severe cases, flatfoot may cause significant deformity and require surgical correction to restore the arch and alleviate pain.