I have had shortness of breath for five weeks now. It was a sudden onset. I feel like I can only take short shallow breaths. I am in fairly good shape, 5 3 , 140 lbs. I work out 6 times per week for 35-45 minutes each time. I run 3.2 miles, 2-3 times per week, stair climb on the treadmill 2-3 times per week, and take yoga. Don t smoke, never have. I have no other pain or symptoms. Chest X-rays were excellent. Spirometery test was normal. Oxygen level has been normal. Blood pressure great. Hemoglobin normal range. Other blood tests all normal. Doctor doesn t have a clue and is at a loss. I Tried an inhahel (albuterol) for three weeks without any improvement. I m now very frustrated and just uncomfortable. What is causing this?