<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have noticed some skin moles on my body and my joints feel stiff and tight. What could be causing this?  <response>: Based on your symptoms, its possible that you have scurvy. This is a condition caused by a lack of vitamin C in your diet. It can cause skin changes, joint pain and stiffness, and other symptoms. Have you been eating a balanced diet lately? 