What are the side effects of having steroid in foot?

Little . Little concern when used appropriately. Steroid injections can be an effective part of a treatment plan for a variety of problems. Your doctor should be able to explain the reasoning behind using medication.
Not much. Depending if oral or injected, it usually removes swelling and pain. If injectable is overused it can cause tissue and bone damage.
Very Safe. When we are injecting steroids in the foot, we are using a small amount over a short period of time (2-3 weeks). Consequently the side effects are very minimal if any. People get into problems with steriods when they are used over a long period of time, such as athletes who are abusing steriods illegally.