The last few days I have had some difficulty breathing, yesterday I was just walking in the neighborhood, after I got about 1 block from the house I got a very bad pain between my breast and couldn't breath, I made it home and rested and got over it, this morning I started walking on my treadmill, after 4 min. the same problem, I set down and it went away, then I started to change sheets on the bed and couldn't finish it got so bad, I then called the dr. Went in to see him, he did an EKG, chest x-ray and blood work, all came out normal, but he is sending me to a cardiologist, he feels something is wrong, so do I. My question is does MS mask other problems like this, I have heard that it can, but I really don't know and I'm sure the cardiologist won't know anything, any suggestions please.