@lummy This has been an ongoing problem since having had radiation in 2003 for stage 4 tonsil cancer. Seasonal allergies exacerbate the problem as well as any respiratory ailment. We have air purifiers in every room and a humidifier in the bedroom. These help. Because of aspiration I am now on a G-tube for all of my nutritional needs. However each morning I have a cup of coffee with ice cream stirred in. Swallowing this helps loosen the mucus and I'm able to clear much of the phlegm. I also take a sip of lime soda or other carbonated beverage to help loosen and cough up the phlegm at other times of the day. I rarely cough in the night. Good luck with this, it is one of many side effects of radiation and chemo, as my ENT said, "Radiation the gift that keeps on giving."... He also told me about 12 years out that he didn't really expect to see me - well it's now 23 years and I'm 80! Take care!