I Am A 67 Year Old Man In Good Health

I am a 67 year old man in good health other than high blood pressure to which I am taking medication for, my problem is my right foot swells up during the day and I have a dark red rash just above my ankle, a little tender to the touch and feels itchy at times, when I move my foot I feel tightness due to the swelling but no real pain, any thoughts on my condition will be fine.