Why does your neck hurt?

Why does your neck hurt?

The most common cause of neck pain is muscle tension from sustained posture, not damage to the spine. Holding your head forward over a phone or keyboard keeps the neck and upper-back muscles contracting continuously for hours. Muscles are built for movement, not for holding one position, and they ache when asked to do the second.¹²

What is actually happening in your neck?

Your head weighs roughly 4.5 to 5.5 kg. Balanced directly over your shoulders, that weight passes cleanly down through the cervical spine and the muscles barely work. Tip it forward and the load becomes leverage.

A widely cited 2014 biomechanical analysis estimated the effective load on the cervical spine at different head angles.³

Those are modelled estimates, not measurements taken inside a living neck, and they are often quoted with more certainty than they deserve. But the direction is not in dispute: the further forward your head goes, the harder your neck muscles work to stop it falling.

What are the most common causes?

Neck pain rarely has a single cause. It usually has a stack of small ones that individually would not bother you and together produce a neck that aches by mid-afternoon. The five below account for the large majority of ordinary, non-injury neck pain, and they overlap: a stressful week and a low screen tend to arrive together.

• Sustained forward posture — phone, laptop, driving, reading in bed
• Stress — the trapezius muscles brace when you are under pressure, often without you noticing
• Sleep position — a night in an awkward position can produce a stiff neck by morning
• Inactivity — muscles that never move lose the endurance to hold a posture comfortably
• Sudden strain — a heavy bag on one shoulder, an awkward lift, a sharp turn of the head

How do you know if it is serious?

Most neck pain is mechanical: it changes with movement and position, it eases with gentle activity, and it improves over days to weeks.² The signs that something else may be going on are specific.

See a clinician promptly if you have:

• pain radiating down into the arm or hand
• numbness, tingling or pins and needles
• weakness in an arm or hand, or dropping things
• neck pain following a fall, collision or whiplash
• fever alongside neck pain or stiffness
• unexplained weight loss, or pain that wakes you at night

Seek urgent care for loss of bladder or bowel control, difficulty walking, or a sudden severe headache unlike any you have had before.

What actually helps?

Movement helps most, and this is the part most people get backwards. The instinct with a sore neck is to protect it and keep still, but prolonged rest lets the muscles stiffen further and lose the endurance they need to hold your head up comfortably. Gentle, frequent movement within your comfortable range is the single most reliable intervention for ordinary mechanical neck pain.

A Cochrane review of exercise for mechanical neck disorders found that specific neck exercise — particularly combining strengthening of the deep neck flexors and the scapular stabilisers with stretching — produces small-to-moderate reductions in chronic neck pain and improvements in function.⁴ The evidence for exercise is stronger than the evidence for most passive treatments.

What that means in practice:

1. Keep moving. Gentle range-of-motion within comfort, several times a day, beats immobility.
2. Strengthen, do not only stretch. Stretching alone eases symptoms temporarily; strengthening changes how long you can hold a posture before it hurts.
3. Change positions often. No posture is good if you hold it for three hours. Movement is the variable that matters, more than the exact angle.
4. Fix the obvious setup problems. Screen height, pillow height, and the shoulder you carry your bag on are cheap wins.
5. Give it time. Muscular endurance takes weeks to build, not days.

How long should it take to improve?

Acute mechanical neck pain typically improves substantially within two to four weeks with gentle movement.⁵ Chronic neck pain — pain lasting more than three months — responds more slowly, and consistency matters more than intensity: a short daily routine outperforms a long weekly one.

If your pain has not improved at all after four to six weeks of sensible self-management, that is a reason to get it assessed rather than to try harder.