Chronic whiplash-associated disorder (WAD) is the cluster of neck and upper-back pain, stiffness, dizziness, headache, fatigue, sleep disruption, and cognitive fog that persists three months or longer after a whiplash injury: usually from a rear-end road traffic accident (RTA).
Around 30–50% of acute whiplash cases transition into the chronic form, and the trajectory is driven less by tissue damage at that stage than by central sensitisation, fear-avoidance of movement, deconditioning, and autonomic-nervous-system irritability.