Quick Question To Anoyone Who Can Help. I Smoke Marijuana

Quick question to anoyone who can help. I smoke marijuana daily and have been for the past 6 years. I'll hold the smoke in till I can't (for about 10 seconds) and for some reason, I get head pressure pains now. Why is this? Everytime I smoke and sometimes when I'm not smoking. I smoke cigarettes too, maybe that's the issue? I'd very much appreciate a response, thank you.