My Fiancé Has Swollen Feet As Of A Few Weeks

My fiancé has swollen feet as of a few weeks ago. They alternate feet and it comes and goes. He was crawling at one point. Thinks it is from an old injury to a ligament that he is not ready
to deal with. The fact that it goes from one foot to the other, tells me otherwise. I don't know if this has any bearing, but he has lost 10% of his body weight over the last year. He is 127 lbs, 5.3 inches and Chinese. I also notice he has been more tired recentley. Likes his beer !