<s>[INST] I have a cough with a choking sensation especially when trying to sleep. It feels as if sand is in my throat . My Dr. Said its probably sinus problems, so I take Flonaise. Initially a little relief, but it s back. What causes this? I admittedly am a 4 cig/day smoker, which I m trying to quit. I m afraid it s throat cancer or something more serious. [/INST] Hello! Thank you for the query. Smoking makes you prone to many lungs diseases including severe inflammation, COPD (Chronic obstructive pulmonary disease) and lung cancer. Throat cancer is also possible. All this diseases give cough so without additional tests you are unable to rule them out. That is why I suggest you to visit pulmonologist, have chest X-ray (or better chest CT) and spirometry (blow test). Palynologist can diagnose throat cancer. Hope this will help. Regards. </s>