Updated March 12, 2015.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Shoulder blade pain can be confusing, because the causes aren’t always obvious. This symptom can be a sign of something as simple as sleeping wrong, or as serious as lung cancer. What should you know if you are experiencing this symptom?

Shoulder Blade Pain Symptoms

Before talking about symptoms, it helps to describe exactly what location we are talking about when describing the shoulder blades. The shoulder blades – medically known as the scapulae – are the triangular shaped bones of your upper back that stick out and become more visible when you extend your elbows towards your back.

The shoulder blades have many functions, one of which is to support pivotal movements of the shoulder.

Pain in the region of the shoulder blade can be due to many causes. It may be due to inflammation in the scapula itself, or referred pain from other areas of the body. Which shoulder blade is affected is an important question, as some conditions are more likely to affect the left shoulder blade, and others more likely to affect the right.

This article talks about pain that occurs in the shoulder blades rather than the shoulder. If you are experiencing pain in your shoulder, check out these articles:

• Shoulder Pain Symptoms
• Shoulder Pain Causes
• Can Shoulder Pain be a Symptoms of Lung Cancer?

Possible Causes of Shoulder Blade Pain

Pain in the shoulder blades can be related to inflammation or trauma to the shoulder area itself, or may instead be due to referred pain from other regions in the chest and abdomen. Because of this, pain experienced in this area can be something simple as a mild muscle strain, or as serious as a heart or lung condition or cancer.

Some conditions are more likely to affect the shoulder blades on one side. For example, gallbladder disease may cause referred pain in the right shoulder, whereas heart conditions are more likely to cause referred pain to the left shoulder blade. Some possible causes include:

• Muscle strain – Short-term overuse of your arms and upper torso may be experienced in your scapula, and is the most common cause of shoulder blade pain. Even something as simple as sleeping in the wrong position could be a cause of this pain. In general, muscle strains often feel "like a pulled muscle" and are more likely to be the case if you’ve started a new exercise program, done lifting that you are not accustomed to, or slept in a new or different bed. Muscle conditions such as rotator cuff tears may also cause pain in this region.
   
• Disc disease – Compression of nerves in the neck by collapsed or displaced discs may result in referred pain to the shoulder blades.
   
• Heart conditions – Referred pain from the heart to the shoulders, shoulder blades and back, as well as the left arm may occur with heart problems, especially in women. Conditions such as heart attacks, pericarditis (inflammation of the lining of the heart,) or aortic dissection may be experienced as pain in the left shoulder blade.
   
• Fractures – The scapulae are a few of the most difficult bones in the body to fracture, and it’s unlikely that you could receive a scapular fracture without remembering the cause. Fractures occur most commonly during car accidents or falls.
   
• Shingles – Shingles, an infection caused by the same virus that causes chickenpox, may cause shoulder blade pain. This is usually followed within a few days by a rash.
   
• Bone metastases – Spread of tumor to the scapula from cancers such as breast cancer, lung cancer, esophageal cancer, and colon cancer, as well as several other cancers may cause pain in the shoulder blades.
   
• Lung tumors and lung conditions – Pancoast tumors, are a form of lung cancer that grows on the tops of the lungs, and typically causes pain in the shoulders, shoulder blades, and arms, rather than the more typical symptoms of lung cancer. Lung conditions such as pulmonary emboli (blood clots in the legs that break off and travel to the lungs) or a pneumothorax (a collapsed lung) are also possible causes.
   
• Arthritis – Arthritis, either in the shoulder or shoulder blade, or in the neck resulting in referred pain, may be a cause of scapular pain.
   
• Osteoporosis – Osteoporosis – a thinning of the bones – may occur in the shoulders, shoulder blades, or neck, resulting in shoulder blade pain.
   
• Abdominal conditions – Disease of organs in digestive system are not uncommon causes of referred pain to the right shoulder blade. Some of these include gallstones, peptic ulcer disease, and liver disease. The pancreas is part of the digestive system, but pancreatitis is more likely to cause pain in the left shoulder blade.

Questions Your Doctor May Ask?

• Which shoulder blade is painful? Your right, your left, or both?
• How long have you been having the pain?
• Did the pain come on gradually or suddenly?
• Have you changed your exercise routine lately?
• Do you participate in activities that often cause pain in the shoulder or shoulder blade? For example, tennis, golf, swimming, basketball, badminton, racquetball?
• Is the pain on the same side of your body you sleep on?
• How would you describe your pain? For example, is it sharp or dull, superficial (on the surface) or deep, burning or achy, stabbing or steady?
• What makes the pain worse? For example, do certain movements, a deep breath, or eating make the pain worse?
• What makes the pain better?
• What other symptoms have you been having? For example, shortness of breath, pain in other regions of your body, coughing, chest pain, or abdominal pain.
• Do you, or have you ever smoked?

Diagnosis

Your doctor will begin by taking a careful history and doing a physical exam. Many causes can be diagnosed based on your history. She will perform a careful physical exam, but studies suggest that it’s difficult to diagnose the cause based on physical exam alone. Depending on this, other tests may include:

• Radiological studies. These may include a chest x-ray, a CT scan of your chest or other regions of your body, an MRI of your chest or other regions, and/or a PET scan if you have a history of cancer.
   
• Heart tests. If she is concerned that you may have a heart condition, tests such as an EKG or stress test may be recommended.
   
• Abdominal exams. Tests such as endoscopy may be done to evaluate your stomach and small intestine.
   
• Bloodwork. Blood tests may also be done to evaluate your liver, to test for some types of arthritis, and several other conditions.

Treatment

The treatment of shoulder blade pain will depend on the underlying cause of the pain. If it is related to overuse, treatment may be as simple as rest. For pain related to the spread of cancer, options include radiation, chemotherapy, and sometimes surgical procedures to alleviate the pain.

When to Call Your Doctor

If you have shoulder blade pain that persists beyond a few days it is important to make an appointment to see your doctor. If your pain is severe, or is accompanied by symptoms of chest pain or shortness of breath call 911 or your doctor immediately.
<sub>Sources:

Choi, H., Lee, P., and K. Kim. Scapuloplasty alleviates scapular pain resulting from lung cancer metastasis. Pain Physician. 2010. 13(5):485-91.

Kibler, W., Sciascia, A., and T. Wilkes. Scapular dyskinesis and its relation to shoulder injury. Journal of the American Academy of Orthopedic Surgeons. 2012. 20(6):364-72.

O’Keefe-McCarthy, S. Women’s experiences of cardiac pain: a review of the literature. Canadian Journal of Cardiovascular Nursing. 2008. 18(3):18-25.

Tanaka, Y. et al. Cervical roots as origin of pain in the neck or scapular regions. Spine. 2006. 31(17)E568-73.

Wright, A. et al. Diagnostic accuracy of scapular physical examination tests for shoulder disorders: a systemic review. British Journal of Sports Medicine. 2012 Oct 18. (Epub ahead of print)</sub>