How would i know if i have a hairline fracture in my foot?

Radiographs: The best (and least expensive) way to determine if you may have a fracture is a simple series of x-rays. If these are not conclusive your doctor may order a more advanced imaging modality (such as an MRI or ct) depending on what exactly your physician is looking for.

X-ray: Have a podiatrist take an xray.

A foot x-ray: Foot x-rays will diagnose most obvious fractures of the foot. There are less obvious forms of injury, such as a stress fracture that might require specialized testing (such as a bone scan or mri). These can detect bone injury where normal x-rays cannot.

X-ray: Only sure way is to take an x-ray, however in some instances x-ray do not demostrate the fx but clinically you feel there is a fx(stress fx) a bone scan with help in making that diagnosis.