About 6 years ago, I had it extremely badly, eventually getting to the point I couldn’t stand up for a month. It turned out to be due to a herniated disc severe enough to need surgery or risk nerve damage.
It’s very rare for it to be that serious (especially, apparently, in young women, and I was in my 20s at the time, which is why my doctor took so long to pick up on it), but it is possible. If it’s been going on a while or gets really bad, see a doctor.
I’d steer clear of chiropractors personally; my doctor sent me to one, and if anything he made it worse, as he manipulated my back without checking what the actual problem was. Turned out the problem wasn’t what he thought. He did stop immediately when I said it felt worse rather than better, and tell me that wasn’t normal, go back to the doctor and request a scan, but it went from sciatic pain to pain plus weird sensations (among other things it felt like my shoe was full of water, really odd) mid session.
Eta: Post surgery it’s almost completely gone. I get the odd tiny twinge, but that’s been it in 6 years.