Pain on the top of the foot can be caused by stress fractures, tendonitis and arthritis, according to Podiatry Network. Diagnosis is conducted by X-rays, MRIs and CT scans.
Pain that suddenly occurs atop the foot in the absence of injury may be caused by a stress fracture, such as that of a metatarsal bone, which is a bone behind the toes. The navicular bone on the top and inside of the foot may also fracture, reports Podiatry Network. This injury is generally sports-induced.
Extensor tendonitis also causes pain on the top of the foot, notes Podiatry Network. Excessive tightness of the calf muscle is a common cause of this condition, as it inflames the tendons leading to the toes. Degenerative arthritis can cause swelling or "thick" feet, and it is seen in people with a falling arch or flat feet. Tarsal coalition, the result of abnormal fusing of two or more bones in the mid-foot region, is seen in children and young adults and can be hereditary. Pain in the Sinus Tarsi, which is a bone canal just below the ankle joint on the outside of the foot, can be caused by flattening the foot, thereby pinching its small ligaments, and by jamming the bones that border the canal.