How are you? I hope you and your family are in good health. White phlegm is usually normal. You do not need to worry about this. Phlegm is just mucus produced by our body, this can in in response to an irritant such as smoking
. Phlegm can be due to post nasal drip
which occurs due a bone in the nose being displaced to one side, you need not worry about this either as it is very common and does not cause any problems. Phlegm can be caused by Acid reflux
from your stomach.
What i suggest you do is quit smoking if you do smoke, secondly remove irritants from your surrounding. Try to raise the head side of your bed by putting a brick under its legs, that will help you with the acid reflux.
Please keep the color of phlegm in check and if it changes its color to green or red. Please do see a doctor.
Take care of yourself.