If I suspect hair loss, would it be a good idea to check hair thickness as well?

It seems like the amount of hair falling out when I wash it hasn't changed much.

However, I feel like the hair on the top of my head has gotten thinner than before.

When I think of hair loss, I usually think about the amount of hair falling out first, but I heard that hair thickness is also an important criterion.

If these changes have started, would it be a good idea to get a scalp examination?

I would like to know what parts I need to check initially.