Excuating pain in feet, right leg & stiffness in both wrists What could be the cause?

Inflammatory problem. see a rheumatologist this may represent the start of aninflammatory or autoimmune condition like rheumatoid arthritis. Some viruses or infections can cause the same symptoms.
Depends. With the limited amount of symptoms that you describe, this could be just about anything. I would make an appointment with your physician to discuss all of your symptoms, complete an examination, and discuss any additional evaluation/ treatment options. Good luck!