Is it Sciatica? Anyone have similiar issues with Sharp pains?

Hi everyone. I’m new here and hoping to get some insight about back pain I’ve been dealing with.

About a month ago, I started having lower back pain on the left side, just above my buttock. At first it was mild and only hurt when I twisted or bent over. Then I spent about three hours bent over going through boxes in my basement, and afterward my entire back was sore to the touch.

After about a week, most of the soreness went away, but the pain in that lower-left area never improved and has actually gotten worse.

What’s strange is how inconsistent it is. When I’m sitting, I feel fine, no pain at all. When I stand up, I’m okay for about three minutes, and then I get a sharp, stabbing pain with even the slightest twist or step. If I push through it for a bit, it eases up and I can walk around with very little discomfort.

But when I sit back down, the pain hits hard again, sharp, stabbing, even making it difficult to take a deep breath. After sitting for two or three minutes, it settles down and I’m fine again.

I went to the ER and had a CT scan of my kidneys, bloodwork, a urine test, and some X-rays. Everything came back normal. They told me it was musculoskeletal, but I’m starting to worry because it isn’t improving, and I’m honestly dreading every time I have to get up or move.

It’s never a dull ache, only sharp pain when I move, stand straight, bend, or twist. It’s worst right when I first stand up or first sit down.