If you're vaping frequently or using too high of a nicotine strength you may just need to slow down. I get that feeling sometimes when I'm tasting new flavors or cleaning and filling my cartos (I test them all until they are working the way I want)
Sometimes if I vape too much it'll give me a headache as well, which tells me to slow down a bit.
If you're concerned though, you might want to get checked out just to make sure you're not having a reaction to a particular ingredient.