Runner with sharp pain in left shin. it is not shin splints. sharp pain periodically.

Stress fracture: If it is not shin splints, you can have a stress fracture in your tibia bone. This is less common than shin splints, but is possible. It is diagnosed with an xray sometimes, but sometimes you need an MRI to see it.

Possibly Other Cause: This could be a stress fracture of your tibia, or an inflammation of the lining of the bone that can mimic a stress fracture. If you've recently changed your running route, intensity or duration; changed shoes and the pain is getting worse, have it evaluated by your pcp or a local orthopedic surgeon for the possibility of having a stress fracture.

Shin pain: The pain could be several things. The most severe would be a stress fracture. This is usually manifested by very localized tenderness, as opposed to other causes which would be more generalized pain. "shin splints" and other inflammatory issues such as periostitis and medial distal tibial stress syndrome can be just as painful, but are less serious as they generally do not lead to more severe complications. If left untreated, a stress fracture in the tibia can progress to a full blown fracture. The best thing for you to do is have an xray and an evaluation from an orthopedic surgeon. Not all stress fractures will show up on an initial xray, and sometimes bone scans or mris are needed if indicated. Regardless of the diagnosis, cross training with lower impact exercise is suggested (swimming, aqua jogging, biking, elliptical, etc.).