Is it bad to pop pimples?

Yes. It pushes inflammation deeper, increases the risk of scarring and post-inflammatory hyperpigmentation, and can introduce infection. Topical benzoyl peroxide, salicylic acid, or a retinoid works better; deep painful nodules should be treated by a dermatologist.

Squeezing ruptures the follicle wall into surrounding tissue, which converts a small lesion into a larger inflamed one with a higher chance of leaving a mark.

For an urgent flare, a dermatologist can inject a dilute steroid into a large nodule, which settles it within a day or two without the scarring risk.