Upper left shoulder pain can originate in your spine or back muscles. It could be caused by poor posture or an underlying condition. It may feel dull or sharp and worsen with activity or lessen with rest.

Minor upper back pain on the left side can get better on its own. But if the back pain is caused by a chronic condition, it might persist until you get treatment.

Read on to learn about the possible causes of upper left back pain, including accompanying symptoms, treatments, and when you should visit a doctor.

The back is structurally complex, which means that pain can stem from a large number of different locations and problems.

A diagram of the spine showing the three major subsectionsShare on Pinterest
illustrated by Jason Hoffman

The spine itself can be broken down into three main sections that stretch from skull to tailbone, each consisting of a stack of vertebrae.

The top section, which runs along the back of the neck, is called the cervical spine. The bottom section, which connects the spinal column to the tailbone, is known as the lumbar spine.

The middle portion of the spinal column connects the cervical and lumbar spines with a set of 12 vertebrae. Together, these vertebrae are called the thoracic spine. The area we know as the upper back includes most of the thoracic spine and the lower portion of the cervical spine.

Some causes of back pain involve injuries to vertebrae in the cervical or thoracic areas of the spinal column, while others do not.

Vertebrae are padded on either side by elastic, shock-absorbing disks that enable movement and help protect the spinal cord, a bundle of nerves that runs vertically through the stack.

Upper left back pain may be the result of an injury, pain disorder, or problem with an organ. Possible causes include:

Muscle strain

A muscle strain is a tear or stretch in a muscle. If the strain occurs in your left upper back, you can develop upper back pain on one or both sides.

This can happen if you:

  • repeatedly lift heavy things
  • overwork your shoulders or arms
  • make a sudden awkward movement

Other symptoms include:

Herniated disc

With repeated use or strong force, the disks that pad the spine can tear. A disc that bulges out and ruptures is called a herniated disc.

If the disc is in the middle or upper spine, you might experience upper back pain on one side.

You may also have:


Scoliosis is a skeletal condition where your spine curves sideways. It usually develops in adolescents during a growth spurt. Scoliosis in which the spine curves to the left is called levoscoliosis, and is less common than scoliosis in which the spine curves to the right.

Mild curves typically don’t cause pain. However, by middle age, scoliosis-related back pain is more likely.

Additional symptoms of scoliosis include:

  • uneven shoulders
  • uneven waist or hips
  • one shoulder blade that sticks out
  • uneven arms or legs
  • off-centered head

In severe cases, it can cause:

  • rotated spine
  • lung damage
  • heart damage

Spinal stenosis

Spinal stenosis is a narrowing in the spinal canal, where the spinal cord is located . It’s often caused by bone overgrowths called bone spurs. You’re more likely to develop bone spurs if you have scoliosis or osteoarthritis in the back.

If the narrowing places pressure on your nerves and spinal cord, you might feel pain on one side of your back. Pain on the left side of your back may indicate that the affected nerves extend into to that side of your body.

Common symptoms include:

  • neck pain
  • pain radiating down the leg
  • pain, weakness, or numbness in arms or legs
  • foot problems


Kyphosis is an outward curve of the upper spine.

A mild curve usually doesn’t cause any symptoms. But if the curve is severe, it can cause pain in the lower and upper back.

Severe kyphosis may also cause:

  • pain or stiffness in the shoulder blades
  • numbness, weakness, or tingling in the legs
  • trouble breathing
  • poor posture
  • extreme fatigue

Vertebral Fracture

A fracture in your spine’s vertebrae can cause upper back pain.

Spinal fractures are more common in people with osteoporosis. People with this condition have bones that are weak and porous. If you have severe osteoporosis, a simple activity like reaching across your desk can cause a fracture.

A vertebrae fracture can also happen after a severe accident, such as a:

  • vehicle collision
  • sports injury
  • fall from height

Symptoms depend on the type of injury. This might include:

  • worsening pain with movement
  • weakness
  • numbness or tingling in the arms or legs
Medical emergency

A vertebrae fracture from an injury is a medical emergency. Call 911 immediately.

Poor posture

If you have poor posture, your spine and body are not aligned. This can place pressure and stress on your back muscles.

It’s a common cause for one-sided upper back pain. Other symptoms of poor posture include:

Overly rigid posture “correction” may also be a cause of back pain.


Osteoarthritis occurs when the cartilage at the ends of your bones breaks down. It can happen anywhere in the body, but it’s the most common type of arthritis in the back.

If you have osteoarthritis in your spine, you might have upper back pain and discomfort, along with:

Myofascial pain

Another cause of upper left back pain is myofascial pain syndrome, a condition that creates sensitive trigger points in your muscles. Placing pressure on these points causes aches and pains.

The most common trigger points are in the trapezius muscle, which is located in your upper back.

Myofascial pain syndrome may also cause:

  • weakness
  • poor joint movement
  • tender muscle knots


Pancreatitis, or inflammation of the pancreas, causes pain in the upper abdomen. This pain can radiate to your upper back and worsen after eating.

Acute pancreatitis may also cause:

If pancreatitis becomes chronic, you might have:

Kidney stone

When a kidney stone leaves your kidney, it can cause dull one-sided pain in the upper abdomen. This pain may radiate to other parts of the body, including the lower abdomen, groin, side, and upper back.

Additional kidney stone symptoms include:

Heart attack

A heart attack is a block of blood flow to the heart. The symptoms are different for everyone, but it can cause chest pain that spreads to your neck, jaw, or upper back.

Other symptoms may include:

Medical emergency

If you suspect that you or someone else is having a heart attack, call 911 immediately.


Carrying extra body weight can place pressure on your spine and back muscles. This can lead to soreness or injury.

Lack of physical activity

Neglecting movement and exercise weakens your back and core muscles. This can cause pain throughout your back, including the upper left side of your back.


The natural “wear and tear” of aging is a common cause of back pain. It often starts at around 30 or 40 years old.

Additionally, as you get older, you’re more likely to feel symptoms of back-related conditions like scoliosis.


If you smoke and injure your back, you’re more likely to have long-lasting back pain. Smoking slows down blood flow to the spine, making it difficult for the body to heal quickly.

The frequent coughing of smoker’s cough can also lead to upper back pain.

There are many causes of upper left back pain, so it’s important to pay attention to other symptoms.

Upper left quadrant pain radiating to your back

If the pain starts in your upper left abdomen and spreads to your back, you might have:

  • muscle strain
  • herniated disc
  • kidney stone
  • pancreatitis

Upper back pain on the left side and under your shoulder blade

Causes of pain in the upper left back and shoulder blade may include:

  • muscle strain
  • poor posture
  • vertebrae fracture
  • severe kyphosis
  • heart attack

Upper left back pain while breathing

The following conditions may cause upper left back pain while breathing:

  • muscle strain
  • vertebrae fracture
  • severe kyphosis
  • severe scoliosis
  • heart attack

Upper left back pain after eating

Pancreatitis may cause upper left back pain after eating. It usually occurs after eating a fatty, greasy meal.

Upper left back pain and arm pain

Pain in the upper left back and arm might be caused by:

  • spinal stenosis
  • myofascial pain
  • vertebrae fracture
  • heart attack

To diagnose the cause of your upper left back pain, your doctor might:

  • discuss your medical history
  • ask about your symptoms
  • do a physical exam

They may also request a:

Upper left back pain may be treated with a combination of home or medical remedies. The best treatment depends on the underlying cause and your overall health.

Home remedies

These home treatments are best for minor back pain:

  • Over-the-counter pain medication. Nonsteroidal anti-inflammatory drugs like naproxen sodium and ibuprofen may provide relief.
  • Hot and cold packs. A hot pack or cold pack can relax painful back muscles.
  • Light physical activity. Gentle activity, like walking and stretching, might help minor back pain. The pain can worsen if you don’t use your muscles.

Medical treatment

If your back pain is severe or doesn’t go away, a doctor might suggest a medical treatment, such as:

  • Prescription medication. If OTC medication doesn’t work, a doctor may prescribe muscle relaxers, prescription pain medication, or cortisol injections.
  • Physical therapy. A physical therapist can help you do back-strengthening exercises. They may also use electrical stimulation, heat, or other techniques to relieve pain.
  • Surgery. In rare cases, surgery might be required for structural issues like spinal stenosis.
  • Specialized procedures. For certain conditions, such as kidney stones, pancreatitis, and heart attacks, case-specific treatment at a hospital may be required.

Usually, minor upper back pain gets better on its own. If the pain is severe or doesn’t go away, or if your range of movement is severely restricted without improvement, visit a doctor.

You should also seek medical help after an injury or if you experience:

  • numbness or tingling
  • fever
  • trouble breathing
  • unexplained weight loss
  • difficulty urinating

While back pain is common, it’s possible to lower your risk of getting musculoskeletal back pain. Here are some tips:

  • Practice good posture. Sit and stand up straight. When you sit, position your hips and knees at 90 degrees.
  • Exercise. Cardio and resistance training will strengthen your back muscles and lower your risk of injury.
  • Maintain a healthy weight. Excess weight can place stress on the back.
  • Quit or avoid smoking. This will help you quickly heal after a back injury. Quitting is often difficult, but a doctor can help you develop a smoking cessation plan right for you.

Upper back pain on the left side may be a symptom of a spine or back condition. It can also be caused by an injury or problem with one of your organs.

Home remedies like OTC pain medication and hot packs can provide relief for minor back pain. But if the pain is severe, a doctor might recommend prescription medication or physical therapy.

If you have upper left back pain with a fever or numbness, see a doctor. You should also get emergency help after a serious injury or if you’re having trouble breathing.