Pain on the side of your neck is most often caused by a strained or tense muscle, particularly the large muscle that runs from behind your ear down to your collarbone. Less commonly, it can come from a joint problem in your spine, a pinched nerve, or the cumulative effects of poor posture. Most cases resolve within a few days to a couple of weeks, but certain patterns of pain signal something that needs prompt attention.
The Muscle Most Likely Causing Your Pain
The sternocleidomastoid, or SCM, is the thick muscle running along each side of your neck. You can feel it tighten when you turn your head. Because of its size and the amount of work it does, it’s especially prone to strain and the development of trigger points, which are tight, sensitive knots within the muscle fibers.
What makes SCM pain tricky is that you often feel it somewhere other than the muscle itself. A trigger point in your SCM can send pain into your forehead, sinuses, face, throat (especially when swallowing), or shoulders. It can also cause headaches, dizziness, vertigo, and nausea. Many people assume they have a sinus issue or a headache disorder when the real source is a knotted-up neck muscle.
Another muscle frequently involved in one-sided neck pain is the levator scapulae, which connects the side of your neck to your shoulder blade. It tightens from hunching over screens, carrying a bag on one shoulder, or sleeping in an awkward position. When this muscle seizes up, it produces a deep ache along the side of the neck that worsens when you try to turn your head.
Common Triggers for One-Sided Neck Pain
Repetitive strain is the most frequent culprit. Staring at a computer or phone for long hours forces your neck muscles to hold your head in a forward position, and the side that bears more tension (often your dominant side) tends to hurt first. Weak abdominal muscles and heavier body weight shift your spinal alignment, adding load to the neck.
Mental stress is an underappreciated cause. Many people unconsciously clench their neck and jaw muscles during periods of anxiety or frustration, and don’t realize they’re doing it until the soreness sets in. This kind of tension often shows up on one side more than the other.
Sleep position plays a significant role. Sleeping on your stomach forces your neck into rotation for hours, straining the muscles and joints on one side. Even side sleeping can cause problems if your pillow is too high, too stiff, or too flat. Harvard Health recommends using a pillow that supports your neck at a higher level than your head when sleeping on your side, keeping your spine in a straight line. A pillow that’s too tall pushes your neck into a bent position all night, and you’ll wake up stiff and sore.
Facet Joint Pain
Your cervical spine has small paired joints called facet joints at each level. When one of these joints becomes irritated or inflamed, it typically produces pain on one side of the neck that doesn’t radiate past the shoulders. This is one of the hallmarks that distinguishes facet joint pain from a pinched nerve: you feel it locally, not shooting down your arm.
Facet joint pain tends to have a static quality, meaning it doesn’t always correspond to a specific movement. Turning your head or tilting it backward often makes it worse or feels restricted. There are no neurological symptoms like tingling or weakness. The pain can become chronic if the underlying irritation isn’t addressed, but it often responds well to physical therapy, gentle mobilization, and correcting the postural habits that aggravated it.
Pinched Nerve in the Neck
A pinched nerve, or cervical radiculopathy, happens when a nerve root exiting your spine gets compressed by a herniated disc, bone spur, or narrowing of the spinal canal. The pain typically starts in the neck but radiates into the shoulder, arm, or hand, often with tingling, numbness, or weakness in those areas.
In more than half of cases, the C7 nerve root is the one affected, and about a quarter involve the C6 root. Both of these exit the lower part of the cervical spine, which is why pinched nerve pain tends to travel down the arm rather than up toward the head. If your side-of-neck pain stays local and doesn’t involve any arm symptoms, a pinched nerve is less likely.
How to Ease the Pain at Home
For muscle-related neck pain, gentle stretching can make a noticeable difference. One of the most effective stretches targets the levator scapulae:
- Seated levator scapulae stretch: Sit tall and actively pull your shoulder blade down on the painful side. Drop your chin to your chest, then rotate your head about 45 degrees toward the opposite side. Place your hand on top of your head and gently pull until you feel a stretch along the side of your neck. Hold for a breath, then try to lift your head against your own hand resistance for 6 seconds. Relax, exhale, and deepen the stretch by tucking your chin further. Repeat two to three times.
Ice can help in the first 48 hours if the pain came on suddenly. After that, warmth (a hot shower directed at the sore side, or a heating pad) tends to loosen tight muscles more effectively. Avoid holding your phone between your ear and shoulder, and if you work at a desk, position your monitor at eye level so your neck stays neutral.
For sleep, avoid stomach sleeping entirely. If you nap while traveling, a horseshoe-shaped pillow can keep your head from dropping to one side, though one that’s too thick behind the neck will push your head forward and create a different strain.
When the Pain Needs Urgent Attention
Most side-of-neck pain is muscular and harmless, but a few patterns require immediate evaluation. Go to an emergency room if your neck pain follows a traumatic injury like a car collision, fall, or diving accident. Muscle weakness in an arm or leg, or difficulty walking alongside neck pain, can indicate a more serious spinal problem. Severe neck pain with a high fever may signal meningitis, an infection of the membranes covering the brain and spinal cord.
Pain that came on suddenly without an obvious trigger, is unusually severe, and involves pain around one eye could, in rare cases, point to a problem with the carotid artery on that side. This is uncommon, but it’s worth knowing about because it requires fast treatment.
If your pain has lasted more than two weeks without improvement, or if it keeps coming back in the same spot, that’s a reasonable point to get it evaluated. Persistent one-sided neck pain that doesn’t respond to stretching and posture changes may involve a facet joint issue or an early disc problem that benefits from targeted physical therapy.