The atlantoaxial joint sits at the very top of the neck, right under the skull. When the first two vertebrae slip out of line, the body sends loud, clear warnings.

Neck pain is the first and most constant clue. It feels deep, like a rod poking upward from the base of the head, and gets worse with the slightest nod or turn.

Headache follows the same track, wrapping around the back of the head and behind the eyes. Coughing or sneezing can shoot sharp pain up the scalp.

Neck motion stiffens. You may find yourself turning your whole body instead of just the head, and backing up the car becomes a shoulder-checking nightmare.

Numbness or tingling can travel into both hands, the face, or even the tongue. Some people say it feels like wearing a too-tight bike helmet.

Muscle weakness shows up in the arms or legs. Grip strength fades, handwriting wobbles, or one foot may drag and catch on rugs.

In severe slips, balance fails. Walking turns clumsy, as if the ground is tipping, and quick head moves can make the legs buckle.

Rare but dangerous: sudden trouble breathing or swallowing. If the slip presses on the spinal cord, the voice can turn hoarse and the throat may feel blocked.