<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, Ive been experiencing some blood in my urine and knee pain. What could be the cause of this?  <response>: Based on your symptoms, you may be suffering from Von Hippel-Lindau disease. This is a rare genetic disorder that can cause various types of tumors to grow in different parts of the body, including the kidneys and joints. Note: This dialogue is for educational purposes only and should not be taken as medical advice. If you are experiencing any concerning symptoms, please consult with a healthcare professional. 