Flat feet running foot pain may be due to excessive exercise, Achilles tendonitis, plantar fasciitis and so on, often used in the treatment of general treatment, drug treatment, physical therapy, surgical treatment and so on. 1. Excessive exercise: The low arch of the foot leads to weakened shock absorption and buffering ability, which is more likely to cause running foot pain, so you can take more rest and reduce weight bearing. 2. Achilles tendonitis: when running with flat feet, the pressure on the Achilles tendon increases, resulting in its swelling and pain, you can take diclofenac sodium extended-release tablets for pain relief. 3. Plantar Fasciitis: Running with flat feet can cause the plantar fascia to carry extra pressure, causing pain and inflammation. For treatment, ibuprofen tablets can be taken to reduce pain, and massage and footbath treatment are also available. Conservative treatment is ineffective, and the damaged portion of the plantar fascia can be removed endoscopically. There may be other reasons for running foot pain with flat feet, so it is recommended to go to the hospital in time, and the above medication should be taken under the guidance of a doctor.