Excessive phlegm can be a sign of respiratory infection, asthma, COPD, bronchitis, allergy, sinus problems or airway irritation and should not always be ignored. Learn about the causes, warning signs, diagnosis and treatment of persistent mucus and chest congestion. Consult Dr. S. N. Gupta, best pulmonologist in Lucknow, at Sanjivini Super Speciality Hospital, a trusted Best Lungs Hospital in Lucknow, for expert evaluation of cough, excessive phlegm, wheezing, breathlessness and other lung-related symptoms. Proper diagnosis can help identify the underlying condition and guide suitable respiratory care.