Pain on the outer side of the foot with accompanying symptoms of swelling and bruising can indicate a fracture of the metatarsal bone, according to WebMD. Additional causes of pain on the side of the foot include nerve damage, tendon inflammation and foot trauma.
Pain on the side of the foot can also signify a bunionette, also referred to as a tailor's bunion, according to Houston Methodist Orthopedics and Sports Medicine. Bunionettes are hardened lumps that develop on the joint that connects the pinkie toe to the foot. Additional symptoms include swelling of the affected area and callused skin surrounding the pinkie toe. Treatments for bunionettes include bunion pads or surgical procedures to minimize the size of the lumps.
Foot pain that occurs on one side can also indicate an injury to the peroneal tendons, according to Foot Health Facts. The peroneal tendons are located behind the ankle bone and connect to the mid-foot and the arch. Injuries, such as tears or trauma, can cause pain and additional symptoms, such as swelling, foot weakness and warmth. Non-surgical treatment methods for peroneal tendon injuries include ice therapy, immobilization, heat therapy, and medications to help minimize inflammation. Certain peroneal tendon injuries may require reparative surgery followed by physical therapy.