How Can Leg Pain And Swelling With Headaches Be Treated?

Hi . My father age is 64 years. He has too much of pain in the base of legs. Lot of swelling is there. This happens every twice or thrice a year. Whenever pain increases headache also starts. As much as the pain.. the headache also increases. He gets weak day by day.. This remain for atleast two or three weeks. During that time he is not able to stand on this legs. The ankle bone joint has also increased in both the legs. Uric acid is normal. & all other reports come normal all the times. We have consulted many doctors. What to do.?? He is in too much pain.