<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hello Sir,My father, 68 years is having problem in his left leg. He complains of pain right below the knee but sometimes it goes down also which makes him unable to walk.Please advise what could be the reason.Can we visit your clinic for this?Best RegardsZishan  <response>: Hello dear user! Thank you for asking us on Chat Doctor! I understand your concerns about your father and Im trying to give some advice to help improve his health. Pain in lower extremities may occur due to nerve degeneration or compression, due to vascular diseases including veins and arteries, metabolic conditions such as diabetes, etc. To evaluate the current status of your father health I recommend go and do the right examinations such as:- Doppler angiosonography to see the arteries and veins of the lower extremities.- Blood count, sugar and lipids in the blood- Neurologist consultation if it is necessary to rule out any nerve compression which causes pain. I wish you and your father a good health! Please dont forget to give your valuable feedback and five-star rating, to help me assist you in a better way. Click at I Find This Answer Helpful too. Please, write a review about your experience with me. Best regards! Chat Doctor. 