Hello. Thanks for writing to us.

The normal breathing in human beings is regulated by higher centres in the brain. During the act of breathing, our nose responds to the higher centres by alternating the side of the nose that is to be involved in respiration. It means that when the left side of the nose is participating in respiration, the rights of the nose gets blocked, and vice versa. This is called nasal cycle. It is a common phenomenon in every individual. In your case it is the same thing that is happening from your childhood. But Maybe because of infection or a common cold even the left side of your nose is getting blocked.

The discharge that you are getting While you lie down is called postnasal drip. It is usually a sign of nasal obstruction or infection in which excessive amount of secretions are carried a way towards the throat. I would recommend you consult an ENT specialist for a quick physical examination and further assessment.

Hope this helps