I've just had this, apparently one of my thyroids is producing too much calcium, I'm waiting for a referral then an operation, luckily its not come back, too say it was painful is an understatement, it happened overnight, no matter how I stood, sat or led the pain across my lower back, left kidney and down into my groin was intense, I took two Naproxen and eventually the pain went and I got some sleep.
I had some bloods taken and some urine samples, I had blood in the urine, the nurse that took my bloods said she has had it and the closest thing she could compare it to is child birth.
This describe exactly what I had.
https://www.american-hospital.org/en/pathologie/renal-colic-and-kidney-stones
\\Renal colic is characterized by acute, sudden pain in the back or side which radiates to the lower abdomen and groin. The patient may have other symptoms including blood in the urine, nausea and vomiting. No position brings relief, and the pain is so intense that emergency medical care is generally necessary.//