How far does a scalp examination cover when you are worried about hair loss?

I felt like my hair was getting thinner, so I thought about starting by changing my shampoo, but I realized that simply changing the product might not be the answer.

I heard that hair loss management methods vary depending on the cause, so I am thinking of getting a scalp examination first.

I am curious if the examination checks hair thickness or scalp condition, and if additional blood tests are sometimes necessary. I would like to check my condition first rather than trying various things without knowing the cause.