I am a 60 year old female, I am experiencing shortness of breath all of a sudden while I am mowing the lawn. I started walking again, thinking the couple of months with theraphy for my back has caused me to get soft. so a 1 mile in home walk for 17 mins causes me the same thing, so I have to stop and rest as well as get a sip of water. Really bad burning sensation in my chest. Today I am at my desk and I have the slight burning like heartburn. Suggestions has the cause. I am do for my physical on the 18th of the month.