Neck pain on the left side usually results from a benign cause, like muscle strain from sleeping in an awkward position. Sometimes, there may be a more serious cause, such as a tumor or rheumatoid arthritis.

The neck contains the cervical spinal cord, muscles, and major blood vessels that supply the entire body. It is often exposed, which increases the risk of injury to its internal structures.

Many people experience temporary neck pain due to a variety of everyday activities and tasks. However, neck pain also ranks among the top five most common chronic pain conditions.

However, severe or persistent left side neck pain may indicate a more serious underlying medical condition.

This article discusses some causes of pain on the left side of the neck, when to see a doctor, and some treatment options.

a woman holding the left side of her neck because she has pain thereShare on Pinterest
Muscle strain or tension may cause neck pain on the left side.

Numerous factors can lead to neck pain on the left side, including:

Muscle strain or tension

Neck pain often results from muscle strain or tension.

Muscle strain occurs when a muscle or tendon is overstretched or torn. Muscle tension occurs when a muscle does not fully release after contracting.

People can develop muscle strain or tension in the neck as a result of:

  • sleeping in an awkward position, such as with the neck bent or twisted to one side
  • hunching over or leaning forward for several hours at a time
  • holding a phone between the ear and the shoulder
  • overexerting the neck muscles when lifting heavy objects or exercising
  • collisions or falls that cause whiplash
  • grinding their teeth
  • stress
  • nonspecific causes

These conditions may cause the following symptoms:

  • neck pain or stiffness
  • a decreased range of motion and flexibility
  • swelling in the neck or shoulder
  • muscle spasms in the shoulder
  • numbness or tingling in the arms
  • headaches

Torticollis

Torticollis, or “wryneck,” is a medical condition that causes the neck to bend, twist, or tilt to one side. This condition usually occurs when the neck muscles contract due to:

  • injuries or accidents
  • congenital irregularities
  • neurological conditions, such as stroke or compressed nerves
  • exposure to cold temperatures
  • certain medications
  • infections
  • emotional stress

Symptoms may include:

  • pain and difficulty when straightening or moving the neck
  • headaches
  • balance problems
  • vision problems
  • difficulty walking
  • nausea
  • vomiting
  • fever

Torticollis may resolve without treatment within a few days.

Heat therapy, massage, and stretching exercises can help relax the affected muscles and reduce pain.

Cervical radiculopathy

Cervical radiculopathy, or a pinched nerve, occurs when a nerve root in the cervical spinal cord is compressed. This can happen as a result of a herniated disk, bone spurs, or inflammation.

Cervical radiculopathy can lead to neck pain that radiates down the arm and into the hand.

Other symptoms might include:

  • numbness or tingling in the arm
  • muscle weakness
  • pins and needles
  • reduced reflexes

Cervical spinal stenosis

Cervical spinal stenosis occurs when the spinal canal in the neck narrows, putting pressure on the spinal cord and nerve roots.

The National Institutes of Health (NIH) suggest that spinal stenosis is often due to age-related changes that affect the spine.

Other possible causes may include:

Symptoms develop gradually, and many people do not experience any during the early stages.

They include:

  • pain or cramping in the neck
  • numbness or tingling that starts in the neck and radiates into the arms and hands
  • weakness in the arms, hands, or fingers

Rare causes

Neck pain on the left side may indicate less common but more severe medical conditions, such as:

For mild or moderate neck pain, it is not usually necessary to see a doctor.

Acute neck pain is treatable with rest, home remedies, and over-the-counter (OTC) medications.

If the neck pain is severe, persistent, or accompanied by additional symptoms, however, it is best to see a doctor. Other symptoms may include fever, vomiting, or loss of coordination.

If the neck pain is the result of an accident or injury, seek immediate medical care.

A doctor can diagnose the underlying cause of severe neck pain and advise on the most appropriate treatment options. They can also assess the severity of a physical injury and determine whether a person requires emergency care or physical therapy.

To diagnose the cause of neck pain on the left side, a doctor will carry out a physical examination, during which they will evaluate the range of motion and pain in the affected area. They will also check for visible symptoms, such as swelling, redness, and palpable lumps under the skin.

They may also use imaging tests to look for signs of fractures, muscle strain, or swelling in the vertebrae. These include:

A person should inform their doctor about their current symptoms and any previous injuries they have sustained.

The following at-home treatments may help relieve mild-to-moderate neck pain:

  • resting the affected area
  • avoiding heavy lifting and intense exercise during the recovery period
  • applying heat using hot compresses or heating pads
  • taking warm baths or showers
  • reducing inflammation using cold compresses, ice, or OTC anti-inflammatory medications
  • massaging the neck, to relieve muscle tension
  • stretching, to improve flexibility in the neck
  • gently exercising, to build strength in the neck muscles and improve posture
  • sleeping with a pillow that supports the neck
  • practicing good posture when standing, walking, and sitting

Some types of neck pain require medical treatment, which will depend on the underlying cause.

A doctor may recommend one or more of the following treatments to a person with severe or persistent left side neck pain:

  • muscle relaxants
  • prescription pain relief or anti-inflammatory medication
  • corticosteroid injections
  • physical or occupational therapy
  • a neck brace
  • surgery

Left side neck pain can occur for many reasons, including poor posture, heavy lifting, and sleeping awkwardly.

In most cases, neck pain improves within a matter of days. Resting the affected area and trying some home remedies can help relieve painful symptoms until the neck heals.

For severe or persistent neck pain that lasts for several weeks, a person should consult a doctor.

Neck pain due to severe injuries or underlying medical conditions — such as a compressed nerve, rheumatoid arthritis, or an infection — are also treatable.