What Could Have Caused Loss Of Appetite And Shortness Of Breath?

Hi Dr. I was wondering if I could get some advice on what might be going on. I don t feel my current Dr. knows what to do. For the last 6 months I have had a massive decrease in appetite (Only eat 1 meal a day and a little snack at night), with that I have shortness of breath with a slight painful sensation when I take a deep breath. I have gone from running 2-3 miles 3 times a week to barely going up a flight of stairs with out huffing and puffing, join or muscle stiffness/tenderness. I have had the asthma test done with negative results, full pulmonary function test which came back negative for anything. Stress test with echo and everything was fine. The latest was the pulmonologist ordered a ct scan of my neck and chest. She said that the lungs and neck were fine but the radiologist noted that my spleen was enlarged at 15cm. She ordered cbc and metabolic tests. Haven t heard back but the provider released them online. I can get the numbers as well. thanks for any help