Red and purple again after a month of cracked foot bone, the possible causes are congestion and edema of the foot, secondary injury during treatment and subcutaneous bruising. 1. foot bone cracked a month later and red and purple, may be due to the foot bone cracked after action obstacles, resulting in congestion of the foot, lower limb venous return obstacles, so the foot will have obvious red and purple swelling phenomenon, generally do not have pain symptoms, the patient can be through the massage of peripheral blood vessels, or elevate the affected limb, to promote blood circulation. 2. There is also the possibility that in the process of rest and recovery, inadvertently make the fracture site suffered a second injury, resulting in capillary rupture around the site of injury, blood leakage in the surrounding tissues, thus appearing red and purple symptoms, if the patient has had a second injury may be, it is recommended that early medical care, to find out whether the fracture is displaced. 3. Subcutaneous bruising: After the foot bone is cracked, bleeding and subcutaneous bruising can appear under the skin of the foot, if the amount of subcutaneous bruising is relatively large, it may not be completely absorbed after one month. Then there will be the phenomenon of red and purple again after one month of cracked foot bone. The patient’s foot bone cracked a month after the red and purple, the symptoms continue not to relieve, it is recommended to seek early medical care, clear diagnosis, targeted treatment.