Brief Answer:
cough may be due to different causes

Detailed Answer:
HI, thanks for using healthcare magic

The crackling sound is due to secretions/mucus in the airways of the lungs.

If your cough has been going on for less than 3 weeks then it would be called and acute cough.

The most common cause is an acute infection such as the common cold or flu or bacterial infection. This can affect any aspect of the airways including the bronchi (causing bronchitis- viral or bacterial) or lung tissue itself (viral or bacterial pneumonia).

Viral infection is more likely if there is no fever or significant general unwell feeling.
This would be treated by fluids, rest and continuation of the mucolytic (mucinex) and cough suppressant (delsym)

If you have fever and feel unwell then antibiotics may be needed.

(2) If your cough has been going on for 3 to 8 weeks then post viral cough is the most likely cause.

This is a cough that continues after a recent cough/cold even after all of the other symptoms have gone.

Treated as above.

(3)If your cough has been going on for 8 weeks or more then it would be called a chronic cough.

The most common causes are post nasal drip, GERD and asthma, with post nasal drip being the most common of the three.

In some cases more than one of these may be present.

Treatment would be antihistamines and topical steroid nasal spray eg nasonex, nasocort, flonase or rhinocort since post nasal drip is most common

Summary: (1) if less than 3 weeks likely due to acute infection and should resolve in a few weeks- fluids, rest, continue meds mentioned

(2) if 3 to 8 weeks then may be due to post viral cough

Again fluids , rest, over the counter cough and cold

(3)if more than 8 weeks then most common cause is post nasal drip of mucus to airways- antihistamines and topical nasals spray steroids

I hope this helps, feel free to ask any other questions

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