Questions & Answers about Mam już zmierzone ciśnienie, więc mogę wrócić do domu.
This is a very common Polish pattern: mam + past passive participle.
Here it means something like:
- I have my blood pressure measured already
- more natural English: I’ve already had my blood pressure measured
It emphasizes the resulting state: the measurement is done, so the speaker is now free to go home.
By contrast, zmierzyłem już ciśnienie means I measured the pressure already, which strongly suggests that I personally did the measuring. In a medical context, mam już zmierzone ciśnienie is often more natural, because it does not focus on who performed the action.
Zmierzone is a passive adjectival participle of zmierzyć.
In Polish grammar, this form behaves a lot like an adjective. It agrees with the noun it describes:
Since ciśnienie is a neuter singular noun, the participle must also be neuter singular: zmierzone.
So zmierzone ciśnienie literally means measured pressure.