Just a crick in the neck or worse?

My sibling (28 non-binary) got a crick in their neck this morning- it hurt to turn their neck to the left but they could turn it a bit to the right. We took our dog on a walk and they looked too far to the right and they felt so much pain, it hurt to just keep their neck in a neutral position. It hurts them to lean back, they can only sit up straight and have their head tilted for the least amount of pain. They took two ibuprofen 30 minutes ago, they take a birth control but that is it. They are approx 130-140 pounds, 5 foot 1 inch tall. Is this just a crick in the neck or something worse? And if it is just a crick in the neck, are there tricks to make it go away?