Brief Answer: 4 most common causes Detailed Answer: Hello XXXX! Thank you for asking at XXXX i want you to know the common causes of cough that can be possibly present in you. If start from the most common cause in you, Asthma and COPD both are highly associated with cough. with the advanacement of disease cough always add up to the symptoms and can be controlled by controlling the disease. the 2nd cause can be pulmonary hypertension due to cor-pulmonale. what does it mean is that for long term Asthma the right side of your heart get enlarge and pump the blood with more force and hence you have more pressure on the right side. this is called pulmonary hypertension and one of the symptoms is cough. to know about this you need ECHOCARDIOGRAPHY by a cardiologist. The 3rd cause, being a cardiologist myself, which I encounter most is the signs of Lung Congestions due to heart infarction. but the reason i listed it in the end is that you said your doctor told you that lungs are Ok. what happens in this case is the heart infarction causes weakness of your heart muscle and it cant pump blood effectively hence resulting in pooling of blood in lung and signs of congestions are there. this congestions leads to cough especially at night time and when you lie flat. The last cause can be addition of some drug for your previous heart attack. we usually prescribe ACE inhibitor and 30% patients develops dry cough with this medication. Now you should see a cardiologist nd he will do echocardiography and all heart causes will be excluded. he will also advise you chest Xray and signs of congestions and as well as pneumonia will be excluded. and if you are taking any drugs other than Allegra please tell me here and ill check either It has cough as side effect or not. Thanks Regards Dr.Suleman

---