Sleep with your head elevated
Avoid eating 2–3 hours before bed
Drink warm fluids in the evening
Stay well hydrated during the day
Use a humidifier in your bedroom
Gargle with warm salt water before bed
Try saline nasal rinses if postnasal drip is present
Avoid dairy if it seems to worsen mucus
Avoid alcohol and smoking
Limit caffeine late in the day
Keep your bedroom free of dust and allergens
Take an over-the-counter expectorant if appropriate
Use allergy medication if allergies are the cause
Manage acid reflux with diet and lifestyle changes
See a doctor if phlegm is persistent, severe, or bloody