The pain in the heel of the left foot may be due to two reasons: 1, Achilles tendonitis, usually more common in people who often run and do bouncing sports, is the joint between the Achilles tendon and the heel tuberosity is often strained, resulting in small lacerations, which over time can lead to local chronic aseptic inflammation, pressure pain in the place where the Achilles tendon is connected to the heel tuberosity is more obvious, if the inflammation is more serious, there will also be local redness, swelling, heat and pain. 2. Plantar fasciitis, a chronic aseptic inflammation of the plantar fascia of the foot and the heel node junction, is also more common in people who often walk, run, jump, this symptom is more typical and special, usually in the morning when you get up and get off the ground, the pain is very strong, like a stabbing sensation, but walking for a long time, the pain is relieved a lot. .