I'm a 47 year old woman, in good health. About 2 weeks ago, while playing tennis, I became very short of breath. This has continued now for 2 weeks, usually just when I'm exercising. My appetite has also decreased the past few days. I was at my OBGYN and he said my lungs were clear and my heart sounded ok. My blood work showed very slight anemia and hyperthyroidism. I'm most concerned about this sudden shortness of breath. I'm in good shape and this has me puzzled.