And that next move falls into three levels of care, he adds. 

• Home care: Many causes of pain under the left rib cage will be something you can manage on your own. Home remedies like rest, pain relievers and lifestyle changes can help. “This is a good option if you can identify a relatively obvious cause of your pain or discomfort, such as a rib injury from a recent fall or an intense workout at the gym,” says Dr. Iloabachie. “If you ate a lot of spicy or acidic foods and you know you have acid reflux, go ahead and take a Tums or Maalox and see if that takes care of it.”
• Doctor’s office or urgent care: For situations that aren’t an emergency and the pain seems to come and go or is tolerable, talk to your doctor or visit an urgent care facility to determine your next steps. “If you can identify the cause and it’s relatively benign or that you’ve sought treatment for in the past, I would say start with your regular doctor, or go to your local urgent care,” Dr. Iloabachie says. “Nowadays, you can even do this from home by making a telehealth appointment and go from there.” 
• Emergency department: A good rule of thumb is that if it feels like an emergency, you should go or call an ambulance, says Dr. Iloabachie. Other factors you should consider for yourself or loved ones are if there are other medical conditions that could make a person more vulnerable — such as if they’re immune-compromised or very or old. The type and duration of symptoms, also play a role, he explains: “If your pain is persistent and worsens with exertion or breathing, the cause could be something more serious and even a medical emergency. Call 911 immediately.”

Before explaining what symptoms to look for and next steps for each organ system, Dr. Iloabachie shares an overview of which organs may be implicated in pain under the left rib cage.

What organs are under my left rib cage?

Under the left rib cage, there are several vital organs that play a crucial role in the body. They include the heart, left lung, pancreas, spleen, stomach, left kidney and portions of the large and small intestine. While they are protected by the rib cage — made up of 24 ribs, 12 on each side — infection, inflammation, or injury to any of these primary organs can cause pain to radiate under and around this area. Ischemia, which means the lack of blood flow to organs, is another common theme that may lead to left side pain or discomfort. While rib injuries are one of the more common causes of pain under the left rib cage, unless you’ve recently fallen on — or been hit in — that area, there is likely another explanation.

The cardiovascular system (heart, blood vessels)

• The discomfort persists
• It’s associated with other symptoms that you can’t otherwise explain
• You have a history of cardiovascular disease. 

Older adults, women and those living with diabetes may experience more subtle signs of a heart attack, such as nausea, lightheadedness and fatigue. “It’s critical to know what to look for to avoid any delays in care, which could be deadly,” he notes.

Pericarditis 

While lack of blood flow is sometimes the culprit, inflammation is another possible cause of pain under the left rib cage. When inflammation occurs in the lining of the heart, it’s called pericarditis. This common condition can result from certain infections, autoimmune disease or an adverse reaction to medication. “It tends to cause significant discomfort that people have a hard time ignoring,” Dr. Iloabachie says. “And that’s fortunate in many ways because we can intervene and take care of them before it’s too late.”

What the pain feels like: Pericarditis causes sharp chest pain, pain when swallowing, palpitations (irregular heartbeats) and fever. 

While not necessarily life-threatening, it can lead to deadly conditions like cardiac tamponade. This occurs when there is too much fluid around the muscles of the heart. This can become deadly because it prevents the heart from dilating and contracting effectively.

What to do: Pericarditis most often requires treatment, which may include an anti-inflammatory therapy. If caused by a medication, treatment would simply be to stop taking it. 

Aortic dissection

The aorta is a main artery critical to survival that runs out of the heart and down the chest, into the abdomen. A tear in the aorta is called an aortic dissection, which can cause blood to flow between the layers of the wall of the aorta, leading to a split or dissection. Possible causes of aortic dissection include high blood pressure, certain genetic disorders that affect the connective tissues, drug use or other lifestyle choices.

What the pain feels like: A very sharp, tearing pain can result, “and often extends from the chest to the back, or from the left side rib into the back,” Dr. Iloabachie says. 
Other common symptoms include shortness of breath, fainting, and stroke-like symptoms. 

What to do: Aortic dissection is a life-threatening condition resulting in death in approximately 30% of cases. Call 911 immediately if you experience any symptoms, especially intense chest pain.

The respiratory system (lungs)

There are several conditions that can impact the left lung and cause pain under the left rib cage.

Pulmonary embolism

Pneumonia

Pneumonia is a lung infection, which can be either viral or bacterial. Symptoms include productive cough (meaning it produces mucus), fever, chills and difficulty breathing. Depending on the type and severity, pneumonia can cause serious lung issues and can even be deadly.

What the pain feels like: Sharp pain on the left or right side. “If you have a temperature associated with left sided chest pain, even in the absence of coughing and shortness of breath, we really need to consider that this might be an infection,” Dr. Iloabachie says.

What to do: While viral pneumonia most often clears up on its own, bacterial pneumonia is an infection and requires antibiotics to treat. Call your primary care doctor or visit an urgent care center near you. If symptoms worsen, call 911 or visit your nearest emergency department. “To alleviate any pain, cough or fever associated with viral pneumonia, over-the-counter medications, fluids and rest are your best bet,” Dr. Iloabachie notes.

Pneumothorax

A pneumothorax is a collapsed lung, which occurs when that air escapes from the lung. Instead of filtering oxygen into the bloodstream, it fills the space between the lung and the chest wall (the pleural cavity). This tends to strike people who are tall and lanky; smokers are also at risk. 

Injuries to the chest and certain medical procedures like lung biopsies or mechanical ventilation are some potential causes of pneumothorax.

A partial lung collapse, called atelectasis, can also occur when the tiny air sacs within the lung (alveoli) don’t expand properly — this can affect either a part or the entire lung. Like a pneumothorax, one potential cause is fluid accumulation in the pleural cavity. Others include an obstruction (mucus, foreign objects, or tumors), certain surgeries and anesthesia, which can cause temporary atelectasis during surgery.

What the pain feels like: This tends to produce shortness of breath and a very sharp chest pain, which worsens when taking a deep breath in or coughing. Dr. Iloabachie explains that “It often happens suddenly and can be spontaneous, or the result of a traumatic event. The worst-case scenario is a tension pneumothorax, a life-threatening event where the pressure caused by escaped air in the pleural space prevents the circulation of blood.”

What to do: A pneumothorax can be a medical emergency, depending on its severity. If symptoms are manageable, call your primary care doctor. If your pain is severe or you have trouble breathing, go to the emergency department or call 911. “This does require treatment,” Dr. Iloabachie says. “In minor cases, we give the patient supplemental oxygen, or we place a needle or tube in the chest to let the air out, allowing the lung to expand to its full capacity.”

In some cases, surgery may be necessary to repair the damage.

Pleurisy

The chest cavity plays a role in pleurisy, as well. In this case, inflammation swells the two layers of tissue surrounding the lungs and lining the chest cavity, called the pleura. “This often is the aftermath of a viral infection, particularly if you’ve had a cold with lots of coughing in the previous week or two,” Dr. Iloabachie explains. “There is some residual inflammation there and this can cause a lot of discomfort, which worsens with deep breaths or coughing.” 

What the pain feels like: The irritated pleura layers lack their usual lubrication, leading to friction. As a result, someone with pleurisy may feel sharp, stabbing pain and, if the left lung's pleura is affected, this pain will be felt under the left rib cage.

What to do: If you suspect pleurisy, it's important to consult a healthcare provider. They can diagnose the condition typically through physical examination, chest X-rays, or CT scans. Treatment usually focuses on the underlying cause, such as bacterial infections (treated with antibiotics). Pain relief and anti-inflammatory medications can help alleviate symptoms.

The gastrointestinal system

The gastrointestinal (GI) system runs all the way from the mouth to the rectum and is responsible for the ingestion, digestion, absorption and elimination of food and waste in the body. Due to their location in the abdomen, just below the ribs, organs within the GI system — the stomach, large and small intestines — are a prime source of pain in this region. 

Gastroesophageal reflux disease (GERD)

Peptic ulcers

Peptic ulcers, which are open sores on the lining of the stomach or the upper part of the small intestine (known as the duodenum), can cause pain from the belly to the chest, which can extend to the left side ribs. 

What the pain feels like: This feels like a burning or gnawing sensation, which may worsen when the stomach is empty. Eating can both cause and relieve this pain, Dr. Iloabachie explains. Pain tends to come and go with stomach (gastric) ulcers, and is more consistent with duodenal ulcers.

Common causes include diet, smoking and alcohol consumption. There’s also a bacteria known as Helicobacter pylori (H. pylori) infection, which can disrupt the mucous layer that protects the stomach lining, leading to ulcers. 

“Peptic ulcer disease ranges in severity from minor, causing no symptoms, to dangerous and life-threatening, Dr. Iloabachie adds. “It can predispose people to upper gastrointestinal bleeding.”

What to do: Diet and lifestyle changes can help manage ulcer symptoms, but Dr. Iloabachie urges people to speak with their primary care doctor or see a gastroenterologist. “Symptoms like severe or persistent abdominal pain, blood in the stool, or black, tarry stools require immediate medical attention,” he says. “Regular follow-up with your healthcare provider is crucial to ensure the ulcer is healing and to prevent further complications.”

The treatment for peptic ulcers depends on the cause, which you can learn more about on The Well. 

Gastritis

Stomach ulcers can result from gastritis, which is the inflammation of the stomach lining. It can occur suddenly (acute) or gradually (chronic), and the resulting pain is typically felt in the upper abdomen. Because the stomach sits on the left side of the upper abdomen, directly under the ribs, pain can extend to the left rib cage. 

What the pain feels like: Gastritis tends to cause sharp or burning pain, which often worsens after eating or during periods of stress. An empty stomach can alleviate this pain.

Other symptoms include nausea, bloating and even vomiting. Excessive alcohol consumption, prolonged use of NSAIDs (non-steroidal anti-inflammatory drugs), or bacterial infections are all potential causes of gastritis.

What to do: Simple lifestyle changes can help. If symptoms persist or become severe (such as intense pain, vomiting, or bloody stools), consult a healthcare provider. 

Over-the-counter medications like antacids, proton pump inhibitors or H2 blockers can provide relief by reducing stomach acid. 

Esophageal spasms

Esophageal spasms are sudden, painful contractions in the muscles of the esophagus, a muscular tube that connects your throat to your stomach and transports food. “This is harder to diagnose without extensive testing, specifically an endoscopy,” Dr. Iloabachie says. “But people often find that it’s hard for them to swallow, or that when they swallow, they feel like solid foods aren’t quite making their way down.”

What the pain feels like: These spasms can cause a range of sensations, depending on the type of esophageal spasm. Those include: 

• Diffuse esophageal spasms: These spasms are irregular and can prevent food from reaching the stomach, causing chest pain.
• Nutcracker esophagus: Also called jackhammer esophagus, normal contractions that move food and liquids to your stomach are too intense, and can lead to severe pain when you swallow. Difficulty swallowing is less common in this type of esophagus spasm.

What to do: Symptoms can most often be managed at home. Frequent chest pain or pain swallowing could also be signs of other serious conditions and warrant medical attention from a gastroenterologist.

Pancreatitis

Some may wonder if irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD) are to blame for pain under the left rib cage. But, Dr. Iloabachie says it would be an unusual presentation. “Left side rib pain would be a very atypical presentation for IBS and IBD.”

Irritable bowel syndrome

IBS is an intestinal disorder that causes a wide range of uncomfortable sensations, from cramps and gassiness to bloating and changes in bowel habits, most often felt in the lower abdomen. Constipation and diarrhea are the main symptoms.

Inflammatory bowel disease

IBD occurs when the body’s immune system mistakenly attacks cells in the gastrointestinal tract, leading to inflammation. There are two conditions that make up IBD: Crohn’s disease and ulcerative colitis. Colitis refers to inflammation of the colon. “Although part of the colon, called the transverse colon, is in the upper abdomen, we tend to experience colitis in the lower parts of the abdomen,” Dr. Iloabachie explains. “So, this tends not to be something that you’d feel as pain in the left upper rib area.”

However, Crohn’s disease, he explains, “has a lot more variable presentation. What people tend to complain about, though, is irregular bowel habits and diffuse pain in the abdomen, not localized pain in the left upper rib area. While it certainly can happen, that would be an unusual presentation.”

The musculoskeletal system

Comprised of bones, muscles, tendons and ligaments, the musculoskeletal system supports the body's structure and movement. And when it comes to pain under the left rib cage, it is one of the most common sources. “If you’ve recently experienced trauma to the ribs, that is a pretty good indicator of what might be causing your pain,” Dr. Iloabachie says.

Rib injuries

Other symptoms include swelling or bruising around the affected area and decreased range of motion due to pain.

What to do: For mild to moderate musculoskeletal injuries, Dr. Iloabachie says home care can be effective and includes rest, applying ice to reduce swelling and/or heat to relax muscles and alleviate pain. Ibuprofen or acetaminophen can also help manage pain. “However, If the pain is severe, persistent, or accompanied by difficulty breathing, don’t hesitate to come see us in the emergency department,” Dr. Iloabachie says.

Rib fractures, however, can be dangerous and require treatment. This may include pain management, physical therapy, or, in rare cases, surgery. “If a rib gets dislodged during a major impact, it can break or fracture and then poke through the lining of the chest wall into the lung, causing a pneumothorax,” Dr. Iloabachie cautions. “And there you have two organ systems causing pain in the left side rib at the same time.”

A healthcare provider might also recommend specific exercises or a physical therapy regimen for muscle strains or costochondritis.

Costochondritis

When the cartilage connecting your ribs to the breastbone become inflamed, you likely have a condition called costochondritis. This can trigger pain in the chest wall, but it’s relatively harmless. The cause can be difficult to detect, but viruses, trauma and exertion are some possibilities, Dr. Iloabachie explains. “This is what we call the diagnosis of exclusion, meaning we eliminate all other potential diagnoses until we are left with costochondritis.” 

What the pain feels like: Costochondritis causes sharp pain or tenderness in the costal cartilage, found between the ribs in the area where they meet the breastbone. This can be felt on either side of the chest and it can extend to the left rib cage, back, or abdomen. Swelling or redness in the affected area can also occur, but is less common.

What to do: Often temporary, costochondritis can be managed at home with rest, heat or ice therapy and over-the-counter pain relievers. There is no treatment specific to costochondritis, but Dr. Iloabachie says stronger anti-inflammatory medications, physical therapy, or in some cases, corticosteroid injections may also be used to reduce severe inflammation.

Rhabdomyolysis

Rhabdomyolysis is the breakdown of muscle tissue, which releases a protein called myoglobin into the bloodstream. This is a potentially life-threatening condition that can cause kidney damage or failure, arrhythmias (irregular heart rhythms), seizures, nausea and vomiting.

Rhabdomyolysis can affect any muscle in the body, but when it involves the muscles between the ribs (intercostal muscles) or upper abdomen, it can manifest as pain under the left rib cage. 

What the pain feels like: Rhabdomyolysis can cause a general feeling of muscle stiffness or aching, as well as tenderness or weakness, particularly in the shoulders, lower back, or legs.

What to do: Rhabdomyolysis is a medical emergency. “If you suspect you have symptoms of this condition, especially after intense physical activity, trauma, or prolonged immobility, seek medical attention immediately,” Dr. Iloabachie advises. “A clear sign that the muscle breakdown is excessive is if pain in the muscle is particularly severe and your urine has become dark and discolored.” Avoid strenuous activities that could exacerbate muscle damage until receiving medical care. Patients require close monitoring and treatment, which may include IV fluids to flush out myoglobin from other organs, particularly the kidneys and prevent damage.

• Mononucleosis: Commonly called “mono,” this viral infection is one of the main causes of an enlarged spleen and can affect anyone at any age. But Dr. Iloabachie says it is most often seen in teenagers or people in their early 20s and spreads through saliva exchange — why it is often called the “kissing disease.” 
  • What the pain feels like: Mono produces lethargy, fatigue, muscle aches, fever and, if it causes an enlarged spleen, pain under the left rib cage.
• Blood diseases: Certain blood diseases like leukemia or lymphoma can lead to an enlarged spleen and subsequently cause pain under the left rib cage. “Most will not feel pain as a result of an enlarged spleen, but if it grows to a significant enough size and presses on other structures, it could certainly happen,” Dr. Iloabachie says. 
  • What the pain feels like: Pain or tenderness in the upper left abdomen that ranges from dull and aching to sharp and severe. If the enlarged spleen presses against the stomach, feeling of fullness or discomfort — even after eating a small amount of food — can also occur.

What to do: For an enlarged spleen, treatment focuses on the underlying cause. While mono resolves on its own, blood diseases like leukemia may require chemotherapy, radiation therapy, or targeted drug therapy. If you have symptoms, consult a primary care doctor or specialist. They may recommend imaging and blood tests to examine the spleen and check for abnormalities. 

Multiple myeloma

This blood cancer originates in the plasma cells, a type of white blood cell found in bone marrow crucial to the immune system. Pain from multiple myeloma typically stems from bone damage caused by the spread of cancerous cells that breakdown bone tissue. 

The back, hips and ribs are among the most common sites for injury — including holes in the bone, called lytic lesions, and fractures — which can cause pain under the rib cage. The left rib cage area may be particularly affected if the lesions occur on the left side.

What the pain feels like: Multiple myeloma causes bone pain, which may feel like a persistent dull ache that worsens with motion.

Other symptoms include nausea, constipation, loss of appetite, fatigue, frequent infections, weight loss and kidney problems.

What to do: If you experience any symptoms of multiple myeloma, speak with a primary care doctor or specialist. There is no cure for multiple myeloma, but several therapies are available and can help slow the progression of the disease, as well as manage symptoms.

The genitourinary system

The urinary system is made up of the kidneys, ureters, bladder and urethra and is responsible for removing waste and excess fluid from the body. Kidney stones and urinary tract infections (UTIs) can develop and lead to various symptoms, one being pain under the left rib cage.

Kidney stones

Kidney stones are masses that form from waste products in the urine and collect in one or both of the kidneys, which are partially covered by the rib cage. They can cause pain if they move into the tube connecting the kidney to the bladder, called the ureter. 

While smaller stones may continue to pass without issue, larger stones can get stuck in the kidney or ureter, blocking urine from reaching the bladder. 

What the pain feels like: Severe, fluctuating pain typically starts in the back or side below the ribs and, as the body tries to clear the blockage, moves to the front of the torso and down into the pelvis. When the stone reaches the bladder, it can cause painful urination. “We don’t feel the pain of the stone while it’s in the kidney, it occurs when it enters the ureter,” Dr. Iloabachie says. “And if it’s in the upper ureter on that left side, it can present as pain in the left rib region.”

Other symptoms include bloody or cloudy urine, nausea, vomiting and the urge to urinate frequently.

What to do: Kidney stones can pass on their own, depending on the size and severity of the pain. Drinking water can help flush out small stones. “Aim to drink two to three liters of water per day, along with pain medication as needed,” Dr. Iloabachie advises. 

Seek medical care if you experience severe pain and there are any of the following symptoms: blood in the urine, fever, chills, or difficulty passing urine. A doctor — either your personal physician or one at an emergency department — can administer medication to relax the ureter and allow the stone to pass more easily. For larger stones that cannot pass on their own, surgical options include shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy.

Urinary tract infection (UTI)

One of the risks of untreated kidney stones is a UTI, which occurs when bacteria enter the urinary tract. This can turn into an infection of the urethra (urethritis), bladder (cystitis) or kidneys (pyelonephritis). 

“We tend to think of them as being lower urinary problems, but when UTIs get to be as bad as they can be, an infection in the bladder or urethra can spread up to the kidneys and, if the left kidney is infected, that can certainly cause pain under the left rib cage.”

What the pain feels like: UTIs can cause sharp or dull pain. In addition to frequent and painful urination, other symptoms include fever and chills, nausea and vomiting, cloudy or bloody urine and fatigue.

What to do: UTIs typically require antibiotics to treat. Over-the-counter pain relievers can also help alleviate pain and fever. Speak to a primary care doctor or specialist — especially if you’re prone to recurring UTIs.

“Before the rash actually develops, people can experience pain,” Dr. Iloabachie notes. “This is because the virus lays dormant in the nerves before it resurfaces. So, what you feel is nerve pain, which is notoriously difficult to treat.”

You may also experience headaches, itching, sensitivity to light (photophobia) and malaise. “People often don’t know what it is until a couple of days later, when all of a sudden they see a vesicular rash in a very specific area,” Dr. Iloabachie says.

What to do: The shingles vaccine is recommended for adults older than 50 and can significantly reduce the risk of developing shingles and its complications. Early treatment can help reduce the severity of the symptoms and the risk of complications, such as long-lasting nerve pain. A dermatologist can determine the best treatment, which may include medications to manage pain and symptom duration. Antiviral medications are most effective when started within 72 hours of the rash appearing.