Relax -- it's not common.
What I Learned From Hiring a Coach to Grow My Dick Bigger
The penis has no bones. Dick has chambers that fill up with blood when you're erect.
If you push bigger hard and bend it too far, the chambers can tear. It can happen if you slip out during sex and thrust against your partner's body.
Along with pain, you might hear a popping sound.
Quiz: Is My Penis Normal?
Afterward you may be swollen and bruised. Surgery is usually the best treatment.
Some boys are born with erections. Ultrasounds show that babies can have them in the womb.
Stimulation can cause them -- they're common during diaper changes. If you have an erection that lasts over 4 hours, hurts, and doesn't result from being turned on, you could have a rare condition called priapism. It needs treatment fast. Some erectile dysfunction ED drugs can cause it.