Doc; Occasionally, maybe two to 6 tmes a year, experience swelling of 1/2 of my tongue,I think usually on the right side, It comes on suddenly and can persist for 6 hours or more , slowly subsiding. When it happens it is a chore to swallow and speaking is awkward. I have also had a similar symptom with one foot or the other. A portion of the foot, heal, arch, or side of the foot will swell pretty suddenly, and persist for many hours. Painful , very itchy and hard to walk on it.