You should see a doctor.
It is necessary that you should see a doctor.
You should have a doctor check you out.
You should see a doctor.
I think you should see a doctor.
You had better see the doctor.
You should see a doctor.
You should have a doctor look at that.
You should go to the doctor's.
You ought to see a doctor.
You had better consult the doctor.
You should see a doctor.
You should get checked by a doctor.
You ought to see a doctor.
You had better consult the doctor.
You should see a doctor.