I have tried out the methods below to reduce phlegm and cough for my son when he was young: - switch off aircon at night and avoid fan blowing directly at him. - patting method which using cup shaped hand to pat on his back about 5minutes for a few times in a day to loosen the phlegm. (refer to the picture attached) - while baby is sleeping, try to lie him in an inclined position instead of lying flat. - rub some baby vicks in your hands and apply on baby's feet and wear socks for baby will help in reduce cough during sleep too. - there is a traditional chinese soup remedies you may want to try to boil for your little one to reduce coughing: http://www.thehongkongcookery.com/2014/10/chinese-pear-herbal-tonic-soup.html (not suitable for baby below 1 year old) If your baby's flu is not getting any better, please bring your baby to PD as soon as possible as young babies are prone to bronchitis and pneumonia (lung infection).
Try using baby saline spray or drops. These can help thin mucous and phlegm that might drain down from the nose into the throat. Lay baby on his/her back and put the tip of the saline spray bottle just inside one nostril and squeeze one or two drops into a baby's nose. You can spray a mist into the nose but the former is better as you can control how much goes into baby's nose and it will be less likely to cause baby to overreact. After that, allow baby to rest a few seconds and use a rubber bulb syringe to suction out the nasal passages. Insert the syringe ever so slightly into the nose while the bulb is depressed and then quickly releasing the bulb.
Patting / Percussion Method. You can refer to this video on how to do it. https://www.youtube.com/watch?v=atD91uwOkjg