Possible reasons for audio fluctuations in laptop

I originally asked this question on Electrical Engineering SE and was recommended to ask it here.

I have a Lenovo laptop (IdeaPad S540) and occasionally I face audio issues. At times even at peak volume settings there is very low audio output however I found a way through, whenever I plug in and remove my headphones the volume is restored to normal for some reason.

I feel since the volume is being restored to normal hence there should be no hardware issue but still I want to figure out what exactly is wrong