Two verbs, have and get, can be used in a special way:
they can be followed by an object and the past participle
of a verb. When have and get are used in this way, the
meaning is something like "someone (verb) (object)":

Examples:

She has her her car washed every week. /
She gets her car washed every week.
(Someone washes her car every week.)

He's having his blood pressure checked./
He's getting his blood pressure checked.
(Someone is checking his blood pressure.)

She's going to have her ears pierced. /
She's going to get her ears pierced.
(Someone's going to pierce her ears.)

He had his hair cut. /
He got his hair cut.
(Someone cut his hair.)

I have to have my car fixed. /
I have to get my car fixed.
(Someone has to fix my car.)

They've had their house painted. /
They've gotten their house painted.
(Someone has painted their house.)