Formal:
* Je vais vous prendre la tension. (I'm going to take your blood pressure.) - This is the most common and appropriate way to say it in a medical setting.
* Je vais contrôler votre tension artérielle. (I'm going to check your blood pressure.) - This is a more precise way of saying it, emphasizing the "checking" aspect.
Informal:
* Je vais te prendre la tension. (I'm going to take your blood pressure.) - This is a casual way to say it to someone you know well.
It's important to note:
* In a medical context, it's crucial to use the formal "vous" when addressing a patient, even if you know them personally.
* If you are not a medical professional, it's best to avoid using any of these phrases and instead direct the person to a doctor or other qualified healthcare provider.