Have had a cough for 4 weeks on the dot. when it first started i was out for a day or two coughing up lots of phlegm. about 18 days and most of the symptoms have subsided but still have the cough. i am a smoker, 29 years old, could i have chronic b?

Assume you mean chronic bronchitis? Unlikely at your young age, but I strongly encourage you to work on smoking cessation now, or you will likely develop some degree of COPD eventually. It sounds like you have a persistent cough from an acute bronchitis—type illness now, & the cough is slow to resolve partly due to the smoking. If it persists you need a Dr exam to check for wheezing, etc.

You have a chronic cough following an acute illness. Bronchiectasis, chronic bronchitis and pneumonia should be excluded. A chest radiograph and a visit with your PCP is recommended. A sputum culture and cytologic analysis may be indicated. Smoking cessation program and pulmonary function testing may be arranged by your physician.