6 Causes of Stomach & Shoulder Pain on the left side.
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Introduction: what organs refer pain to the left shoulder?
Shoulder pain can either result from:
- The shoulder itself (bones, muscles, and tendons of the shoulder), Or
- Referred pain from other organs to the left shoulder.
The most common organs that cause referred pain in the left shoulder include:
- The pancreas.
- The spleen.
- The left colon.
- The stomach (rarely).
- The heart.
- The left lung and pleura.
- Irritation of the left side of the diaphragm (Kehr’s sign).
The most common causes of stomach and shoulder pain on the left side include pancreatitis, splenic rupture, splenic abscess, referred pain from the heart, left lungs, and peritonitis in the upper left abdomen.
You will learn the most common causes of stomach and shoulder pain on the left side.
1. The pancreas and left shoulder pain.
The pancreas is a small organ located in the upper left quadrant of your abdomen. It is responsible mainly for producing the digestive enzymes and the regulations of blood sugar (through insulin and glucagon).
The pancreas may become inflamed (pancreatitis) due to various causes. The inflammation can be sudden and severe (acute pancreatitis) or recurrent, prolonged, and less severe (chronic pancreatitis).
The main symptom of acute pancreatitis is often severe pain in the upper central abdomen. However, The pain may extend to the left stomach area and radiates to the back and the left shoulder.
Common causes and risk factors of pancreatitis:
- Gallstones that slip through the bile ducts & reach and obstruct the pancreas.
- Severe increase in blood lipids (serum triglycerides above 1000).
- Some medications.
- Patients who undergo a procedure called endoscopic retrograde cholangiopancreatography (ERCP).
- Severe increase in body calcium levels (as in parathyroid tumors).
- And Others.
Symptoms of pancreatitis:
- Acute pancreatitis starts as a sudden, severe persistent stomach pain.
- The pain is primarily located in the upper central abdomen (epigastric area) and may spread to the left stomach area.
- In 50% of cases, the pain radiates to the back (often to the center of the mid-back).
- The pain may also radiate to the left shoulder.
- The pain starts as severe and persistent meals, which may exacerbate after meals and partially improves by leaning forward.
- Other symptoms include loss of appetite, nausea, vomiting, fever, and changes in bowel habits.
Other pancreatic diseases that cause shoulder pain:
- Pancreatic cancer (reference).
- Pancreatic pseudocysts.
- Pancreatic trauma.
How common is left shoulder pain with pancreatitis?
There are no studies assessing the exact frequency of shoulder pain with pancreatitis. However, from the practice experience, this complaint is not frequent and occurs in a minority of the patients.
The left shoulder pain in pancreatitis is often more common in complicated cases with pancreatic hemorrhage or collection under the diaphragm (reference).
Acute pancreatitis is diagnosed based on the presence of 2 out of the following 3:
- Typical pancreatic pain: acute onset, severe, persistent pain for days in the epigastric area. The pain may spread to the left stomach area, the center of the back, and the left shoulder.
- Elevated serum lipase or amylase (more than three times the upper limit of normal).
- Imaging: abdominal ultrasound, contrast-enhanced CT, or MRI showing changes typical for pancreatitis.
Pancreatitis is a common cause of combined left stomach pain and left shoulder pain, especially in cases of complicated pancreatitis.
2. The spleen and left shoulder pain.
The spleen is a fist-sized organ located in the upper left of your abdomen next to the stomach.
Multiple diseases can cause the spleen to enlarge (splenomegaly). However, not all diseases of the spleen cause stomach pain. Most cases of splenomegaly are painless.
In this section, you will learn the causes of the painful spleen rather than the causes of splenomegaly.
Causes of the painful spleen:
- Splenic infarction (death of a part of the whole spleen) is often due to the cutting of its blood supply, as with sickle cell disease.
- Splenic abscess.
- Splenic rupture (mainly due to the trauma of the spleen.
- Rapid enlargement of the spleen.
- Splenic tumors include lymphoma, multiple myeloma, metastatic tumors, and other blood malignancies.
- Acute infections include viral (cytomegalovirus, infectious mononucleosis), malaria, infective endocarditis, etc.).
Splenic rupture (due to trauma or severe splenic disease) is one of the most common causes of combined severe left stomach pain and left shoulder pain.
The symptoms of spleen pain vary depending on the cause.
- Upper left stomach (abdominal) pain.
- The pain may or may not spread to the left shoulder, depending on the causes. The pain is referred to the left shoulder when splenic rupture, collections around the spleen, or inflammation of the splenic capsule.
- Fever in many cases (particularly splenic infections, tumors, abscess, and rupture).
- In severe cases (such as rupture or abscess): severe abdominal tenderness over the spleen area.
- Nausea and vomiting.
- Shortness of breath.
- Symptoms of complications such as confusion, lightheadedness, or coma.
The most important diagnostic tests for the spleen conditions include:
- Abdominal ultrasound.
- CT (computed tomography) of the abdomen.
- Peripheral blood examination for abnormal (malignant blood cells).
- Full blood count.
- Bone marrow aspiration or biopsy (to detect blood malignancies).
- Testing for infectious organisms (viruses, bacteria, etc.).
- Splenic biopsy if the cause is unknown.
3. The heart.
Although we are talking about stomach pain, we should also consider the heart as a cause of both stomach pain and left shoulder pain.
Your heart lies in your chest cavity just above the diaphragm. As a result, most painful heart diseases cause chest pain rather than abdominal pain.
However, your heart can cause chest and abdominal pain in certain cases. Even more, some heart conditions may cause stomach pain without chest pain.
The most common heart conditions that may cause stomach pain and left shoulder pain include:
A. Heart attack (acute coronary syndrome or myocardial ischemia).
Myocardial ischemia (coronary heart disease or heart attack) is a partial or complete loss of blood supply to a portion of the heart muscle.
When the blood supplying the lowermost part of the heart muscle decreases or stops, severe pain arises from the heart.
However, the pain in inferior myocardial ischemia is felt in the upper stomach. Commonly, the pain also radiates to the left shoulder and the left arm.
- Typical chest pain (compressing or burning) pain in the front of the chest. The pain may radiate to different sites (the jaw, left shoulder, and the epigastric area.
- Some cases may cause atypical pain (such as inferior MI) presenting with stomach pain (without chest pain), which often radiates to the left shoulder.
- The pain onset is often related to physical exertion or mental stress (rather than meals).
- The pain improves by resting or taking sublingual nitrates (a medication that dilates the coronary arteries).
- The pain onset is often sudden, lasting for a few minutes up to hours or days.
- In severe cases, it may cause serious life-threatening complications such as heart arrhythmia (rapid and/or irregular heartbeats) and shock (cardiogenic shock, which manifests with the symptoms of low blood pressure).
- You should consider heart attack if you have a history of previous attacks or risk factors (older age, smoking, hyperlipidemia, family history, diabetes, hypertension, etc.).
Your heart is enveloped in a double-layered membrane or sac called the pericardium. Sometimes, this layer becomes inflamed (often due to viral infection), leading to pericarditis.
The pericarditis pain often presents with chest pain that may radiate to the upper stomach and the left shoulder.
4. The lungs and the pleura.
Some diseases affecting the left lung and the left pleura (a thin double-layered membrane enveloping the lungs) may give rise to chest pain, stomach pain, and left shoulder pain.
The disease affecting the lower part of the left lung and the pleura (irritating the left diaphragm) commonly causes left shoulder and upper left abdominal pain.
Common causes include:
- Pneumonia (chest infection) affects the left lower lung lobe.
- Lung cancer (left lung or bronchi).
- Pulmonary embolism (obstruction of the pulmonary arteries carrying blood to the lungs).
- Lung abscess in the lower left lung.
- Pleurisy (pleural inflammation) affecting the lower left pleura.
5. Diaphragmatic irritation (Kehr’s sign).
Kehr’s sign is a term that describes acute pain in the tip of the left shoulder due to the irritation of the undersurface of the left diaphragm.
Any collection of fluids, blood, or other irritants in the upper left stomach area just below the diaphragm often results in left stomach pain and pain at the tip of the left shoulder (reference).
The most common cause of such a condition is the spleen rupture (due to trauma or infectious mononucleosis). The pain is often worse when the patient lies down with his legs elevated (reference).
The collected fluid often irritates the phrenic nerve supplying the diaphragm. As a result, phrenic nerve pain often radiates to the tip of the left shoulder.
Other causes of diaphragmatic irritation include:
- Severe abdominal trauma (blunt).
- Ruptured ectopic pregnancy.
- Phrenic artery rupture.
- Splenic abscess.
- Acute pancreatitis with a hemorrhagic collection.
- Perforated bowel (in the upper left stomach area).
6. IBS and left shoulder pain.
IBS is one of the most common causes of chronic or recurrent stomach pain. The pain can be diffuse all over the abdomen or localized to a specific region of the abdomen (such as the left stomach area).
IBS doesn’t typically cause left shoulder pain during flare-ups. However, many people with IBS also have chronic pain conditions such as fibromyalgia.
Studies estimate that up to 20% of patients with IBS have fibromyalgia and other unexplained pain syndromes.
Fibromyalgia is a chronic condition that causes widespread pain all over the body. The shoulder (left and right) is one of the most common sites of fibromyalgia pain.
Symptoms suggestive for IBS & Fibromyalgia:
- Recurrent colicky stomach pain (at least one day per week). The pain is often diffuse or localized into specific locations (such as left stomach pain).
- The abdominal pain is often relieved (partially or completely by defecation).
- The pain is often associated with changes in bowel habits (constipation or diarrhea) and stool forms (loose or hard stools).
- Mucus in the stool.
- Patients with IBS and fibromyalgia often suffer from widespread pain, including shoulder (left, right, or both), neck, back, buttocks, etc.).
- Fibromyalgia pain is often chronic and difficult to treat.
- Associated symptoms include chronic fatigue, brain fog, migraine, mood changes, etc. Learn More.
7. Other stomach problems that may cause left shoulder pain.
- Ovarian cyst.
- Ruptured left ectopic pregnancy.
- IBD (Crohn’s disease and ulcerative colitis). When the left colon is affected, it commonly manifests as left stomach pain that may radiate to the left shoulder.
- Left kidney pain.
- Perforated bowel or stomach.
- Complicated cholecystitis, appendicitis, and other conditions that cause peritonitis.
Bonus: What are the common causes of left shoulder pain (without stomach pain)?
- Broken bones.
- Shoulder dislocation.
- Tears in the tendons of the shoulder joint.
- Muscle strain.
- Thoracic outlet syndrome (left-sided).
- Paget’s disease.