I am a fairly healthy 53 year old woman in good health, 5 7 1/2 and 175lbs. . I take daily supplements of Oscal, Synthroid .125, Multi Vitamin, Vitamin E. I moved from Missouri to Ohio 4 months ago and the move has been without major incident. I am used to walking 3 miles about 3x/week without any issues. Just this week, in the last 4 days, I have noticed that when I start the walk, my chest is getting very tight in the very center of my chest and it s somewhat painful. Thursday and Friday, I was able to continue the walk to approx. 2.25miles, but today, within about 100 yards of walking along the river, the vice like pain in my chest came on again, and I have turned around and come home and taken a baby aspirin. I feel better now that I m inside, although I know that I m no longer walking. I have no pain down my arms, I m not dizzy but I ve been tired most of the day with a headache and I can feel sinus pressure. I m not sure if I m now allergic to something outside that I might not have been exposed to before, but I ve lived here for 4 months now and been on walks for at least 2 months here before this. Thoughts?