General objective of this article is to explain Causes of Hairline Fractures. Reasons for hairline fractures are plenty and perhaps they are quite painful. Hairline fractures also called stress fractures are attributable to repetitive forces acting around the bones usually in places such as the foot and lower limb. Due to an imbalance between your resorption and growth involving new bone tissues in addition to cells, bones are can not regenerate and timely replacement cannot happen. Due to this fatigue, micro cracks available as hairline fractures are finally formed.