Hello. Thanks for writing to HCM. You seem to have a problem related to either your lungs or your heart as these two are responsible for the oxygenation of the entire body. 1. Any lung condition may cause breathing difficulty. It depends whether your symptoms have suddenly appeared or have been slowly developing over a long period of time. If they have appeared suddenly and you also have associated symptoms like fever, phlegm formation, chest pain - it is likely that you have an infection in your lungs i.e. pneumonia or the covering of your lungs. If your symptoms have developed slowly over a long period of time, it indicates a non-infectious cause like a chronic obstructive pulmonary disease (COPD). It is more likely if you are a smoker or have been exposed to some kind of environmental pollutants like smoke, dust, cotton fibres, asbestos fibres, bird droppings, etc. due to your occupation or your place of residence. If you are overweight or obese, obstructive sleep apnea is also a possibility which will also cause sleepiness during the day time. Sleep study will confirm it. 2. Heart conditions like slowly developing heart failure due to any problem of the valves, muscles of the heart, anemia, hyperthyroidism or indirectly as a result of lung condition, may very well be the cause of your symptoms. This is more likely if you also have comorbid conditions like diabetes, hypertension, high cholesterol or any condition which causes your blood to clot. At this juncture, I suggest you visit your doctor for a thorough clinical examination and also tests like a complete blood count, lung function test, chest Xray, an ECG and an echocardiogram of the heart are the basic investigations which should be performed to avoid possible worsening of your condition. Sleep studies may be performed later if everything else are normal. Hope this helps. Wishing you good health. Regards, Dr Geeta