I have chest congestion after lying down. sometimes when i wake in the morning i cough up lots of mucus. no other respiratory symptoms. causes?

Cough: You perceive it in the chest but it really is that you have mucus from your nose which at night drops to the back of yr throat (gravity) where u have cough receptors that make you cough. You should treat your allergies (plenty of OTC meds), get a good HEPA filter for home use and speak to yr doc to get benzonatate 200mg q8h for a few days.