The tendon pain on the inside of the foot is considered to be plantar fasciitis. The inside of the sole of the foot is a body projection area belonging to the plantar tendon membrane, and if the pain on the inside of the foot is caused by frequent weight-bearing walking, going up and down stairs, and excessive physical activity, it should be considered to be a case of plantar fasciitis. The first thing to do is to avoid too much exercise and rest thoroughly, while you can use hot water to soak your feet, use conventional anti-inflammatory and pain-relieving drugs to relieve sterile inflammation and pain, and usually prohibit wearing high heels, because high heels tend to make the weight-bearing point of the foot change, which can make the fascia subject to a greater load, thus aggravating inflammation and pain.