Do You Have To Have Your Neck Adjusted When You Visit A Chiropractor?

It depends on what's going on with you individually.
But the short answer is "no." You do not.
Why wouldn't someone want their neck adjusted? Media is pretty good at scaring us. We see action heroes effortlessly snap the necks of bad-guys right and left, and a chiropractic adjustment can look like someone is doing the same thing. In all truth, the two may appear the same, but are world's apart.
Firstly, your neck is actually very, very strong. It usually takes a lot of force to damage it (contrary to action movie portrayals).
But there have been documented cases of chiropractic induced strokes. This is sad and a travesty to those who this happens to. But, what isn't mentioned is the rate of occurence has been estimated to be 1 in one million on the high end, to 1 in 40,000 on the low end.
No two chiropractic adjustments are the same. Maybe you've noticed this as you've been to more than one chiropractor. You found one adjusted one way, and one adjusted another, and you probably stayed with the one you enjoyed the most. A good adjustment, although is may appear easy, is an art. I kid you not, it takes years to develop the sensory and muscle coordination to deliver an extremely quick, low amplitude adjustment that cavitates a precise joint.
There are other ways to mobilize a joint without the high velocity, low-amplitude maneuver chiropractic is famous for. There are also instruments designed to move joints that can be used as well. To be perfectly honest, this HVLA adjustment has a unique physiological response that is not replicated by slower treatments, but there are still ways around it if a patient so desires.
Patient comfort is extremely important, and a thorough exam should always precede any course of treatment to rule out risks.
It should also be noted that for some, I would even say most, a proper adjustment, when medically necessary, can be the difference between night and day for a suffering patient. Especially longstanding tension-type headaches, neck and lower back pain. Honestly, I have no way to explain this, but I've had people tell me they can see and even smell better after a much needed adjustment.
So if you're concerned, no worries. There's more than one way to skin a cat (That's a horrible analogy, I'm sorry.), and your doc will take care of you.