Am I allowed to deduct medical expenses beyond my FSA? Is FSA already reflected on W2 or do I need to subtract the FSA amount from my total medical expense.

I am not sure since FSA is pre-tax and already deducted, if have to subtract the FSA amount from my total medical expense, which is much higher than the FSA amount. And medical expenses are divided into categories, so I am not sure where/how I am supposed to subtract it if needed. Thank you.