How do i tell if my foot is sprained or just bruised?

Sprain vs bruise: Both sprains and bruising are injuries to the soft tissue of the body. An initial x-ray would show if the injury caused a fracture in the bones of the foot. An MRI allows visualization of soft tissue and can be used to confirm suspected diagnoses of ligament sprains or bone bruises.

Have it looked at: A sprain injury can result in redness, bruising, swelling, pain, and possibly instability of the involved area. An x-ray will be able to assist in differentiating a sprain form a fracture. Have it evaluated by a professional and get the appropriate treatment.