Is there a specific cause for the pain in the left side of the abdomen?

Is there a specific cause for the pain in the left side of the abdomen?

Lately, I am worried because there is a cause for the pain in my left side.

Are there any people with experience related to this?
Is there anyone experiencing left side flank pain?

The location of the pain is precisely in the left side of the waist.
Below the ribs.
Some days, there is pain.
It feels very faint,
Some days, it also feels quite strong.

When moving or sitting,
There are times when I even feel uncomfortable while lying down.

The cause I think of for the left side flank pain is

It hurts a bit when I wake up.

I wonder if I'm sleeping well? Haha.

Are there any possible causes to consider when experiencing these symptoms?
I heard that sometimes these pains can be caused by stress.
Is there a possibility of that happening in my case as well? Or could it be a problem with my kidneys or internal organs?

Please let me know if you have any information about the causes of left side flank pain. Haha