<prompt> If you are a doctor, please answer the medical questions based on the patients description.I ve had three x-rays of my right foot. There is swelling in foot, ankle and part of the leg. It hurts to walk on-like a knife sticking through my foot. Tomorrow I go for an MRI. But the doctor doesn t seem to know what the problem is. There is fever from time to time.  <response>: Hello, Your symptoms seem to be related to arthritis or an infection. I recommend checking inflammation tests complete blood count, PCR, ESR and some other blood lab tests vitamin D plasma levels, blood electrolytes, RF levels, AS tier, ANA and ANNA antibodies. Consulting with a rheumatologist may be needed. Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor. 