.I have a friend (55 years old, female) who gets very breathless climbing stairs or on not very much exertion.  She has never smoked and has been told she does NOT have asthma.  What other explanations might there be for this! - Thanks
Thanks for your question on Chat Doctor. I can understand your concern. Breathlessness on minimal exertion and climbing stairs is mostly seen with heart (heart failure) and lung (bronchitis) diseases. So better to take her to doctor and get done ECG, 2d echo, stress test and PFT (Pulmonary Function Test). Ecg, 2d echo and stress test are needed for heart failure.PFT is must for the diagnosis of bronchitis. She may need diuretics, cardiac supportive Chat Doctor.  Don't worry, she will be alright. Hope I have solved Thanks for. I will be happy to help you further. Wishing good health to your friend. Thanks.