Macbook looks like exploding
HI,
I have 2011 Macbook which was working fine last week but then I woke up with the touch pad slightly open. It looks like something is expanding inside. I left it for a week as I don't know what to do yet. However, it keeps on expanding like something is going to explode. I have important files inside it and I don't know what to do. Please help.
MacBook, OS X El Capitan (10.11.5), null