Why could my neck ache when i wake up?

Bad bedtime habits: It could be a number of things. But, in my experience it is best to start with simple things: bad pillow, bad mattress, stress, poor sleeping habits, or poor posture throughout the day are often causes of neck pain when someone wakes up. Try changing some of your before bed routine, eliminate bad habits, and try basic stretching of your neck muscles prior to going to sleep.

Several reasons: Poor neck support from your pillow can be a cause. An old unsupportive mattress can be a cause. Muscle spasm may result from the above plusany other causes.