My Husband Has Stage 4 COPD And For The Last

My Husband has stage 4 COPD and for the last 3 weeks his left foot is extremely swollen and his left hand as well. he says he hurts from his waist down. he is on blood pressure medication to which his PCP says may be the issue but he doesn't (the Dr) want to change it. My concern is the discomfort, it's only the left side and it does not go down at all even when elevated and in the morning after having it up for 10 hours or more