How to tell if it's kidney pain or back pain?

I started to take Renelix drops (homeopathic drops for kidney function) again yesterday evening. I might've put too much in the water but it's hard to measure. Last night I started having pain on my left back area right at the flank muscle.

I seem to be herxing today. I woke up still with pain in my back and feeling exhausted but couldn't fall back to sleep because of the achiness in my joints, muscle twitching and all around pain. The pain doesn't really move, but it is worse when i lean back. I don't have any urinary or groin pain, but i do feel pressure on my bladder like i have to pee. I've read kidney pain is between your ribs and hips but this is like directly behind my ribs on my back, not below my ribs.

How do I know if it's just back pain or kidney pain?

"directly behind my ribs on my back, not below my ribs"

If its muscle pain doing nothing results in nothing, so some manual hands on detective work is needed. Any sort of deep massage or manual trigger point seeking and releasing will most likely change the pain level for the better or even move its location a little. Stretching(moving) will most likely increase pain.

I had what I know was kidney pain a couple of times - not related to kidney stones. Mine was due to herxing and overloading the kidneys with too many toxins. I felt the pain on both sides of my lower back and it hurt worse if I tried to stand up real straight.

Drink lemon water. Take dandelion root. Epsom salt bath. Sauna. Back off on antimicrobials or whatever may be causing a herx if you added something new or increased a dose. Detox is needed. If it's due to toxins, it the pain will pass in a day or so if you slow down and detox.

If Renelix is supposed to INCREASE kidney function, it could be raising it too much at once and causing overload.