Laptop makes annoying noises, what to do?

Since yesterday my laptop has been making strange noises, it is probably the fan. He runs normally longer and suddenly he starts to make such a loud noise. It sounds like a saw, but of course not that loud. It is extremely annoying and I do not know whether this could be dangerous or whether it is a sign that the laptop could soon break completely? Can anyone help me further?

Opening up and looking, cleaning up can sometimes work wonders

I have no idea how to disassemble something.

Then you should look for someone who has a clue. A laptop can break due to overheating.