What Causes Right Side Pain and When to Worry

Right-sided pain has dozens of possible causes because the right side of your body houses several major organs, each capable of producing pain when something goes wrong. The gallbladder, appendix, right kidney, portions of the liver and colon, and, in women, the right ovary and fallopian tube all sit on the right side. Where exactly the pain is, how it started, and what other symptoms accompany it are the biggest clues to whether you’re dealing with something that will pass on its own or something that needs emergency care.

Upper Right Side Pain

The upper right part of your abdomen, roughly from your lower ribs down to your navel, contains the gallbladder, most of the liver, part of the stomach, and part of the colon. By far the most common reason for sudden, severe pain in this area is an inflamed gallbladder, a condition called acute cholecystitis. It typically happens when a gallstone blocks the duct that drains the gallbladder, leading to swelling, infection, and pain that can radiate to the right shoulder or back.¹ The pain often flares after eating fatty foods, and nausea is common. When imaging confirms uncomplicated cholecystitis, surgical removal of the gallbladder is the standard treatment.

Gallstones can also cause problems without full-blown cholecystitis. A stone that briefly blocks the bile duct produces what’s called biliary colic: intense, crampy pain in the upper right side that lasts anywhere from 20 minutes to a few hours and then subsides on its own when the stone shifts. Because biliary and liver-related problems account for such a large share of upper right quadrant pain, ultrasound is the recommended first-line imaging tool for evaluating it.²

Not every upper right pain is the gallbladder, though. Hepatitis, liver abscess, and even trapped gas at the hepatic flexure of the colon (the sharp bend in the colon tucked under the liver) can mimic gallbladder pain closely enough to fool both patients and clinicians. Hepatic flexure syndrome, where gas accumulates and distends that bend in the colon, creates right upper quadrant discomfort that can feel alarmingly similar to liver or gallbladder disease.³ It tends to come and go with meals and bowel movements and is ultimately harmless, though it can send people to the emergency room before the benign explanation becomes clear.

Lower Right Side Pain

When the pain sits lower, below the navel and toward the right hip, the first concern in an emergency setting is appendicitis. The appendix is a small pouch attached to the beginning of the large intestine, and when it becomes blocked and inflamed, the result is pain that classically starts around the belly button and then migrates to the lower right side over several hours. Nausea, vomiting, and loss of appetite follow in varying degrees, and pressing on the area makes it worse.⁴ Appendicitis typically requires surgery within hours. Delaying treatment raises the risk of the appendix rupturing, which can cause a dangerous abdominal infection.

The terminal ileum, the last stretch of the small intestine before it connects to the colon, also sits in the lower right quadrant and can become inflamed. When this happens, the pain can be nearly indistinguishable from appendicitis. While Crohn’s disease is one well-known cause of inflammation there, a wide variety of other conditions produce the same pattern, including bacterial infections, medication side effects, and reduced blood flow to the area.⁵ Many of these are short-lived and resolve on their own, while others require ongoing treatment. The point is that lower right pain with diarrhea does not automatically mean Crohn’s disease, even though that’s what many people fear.⁶

Right Flank and Back Pain

Pain that wraps around the right side of your body, roughly at the level of your waist or slightly above, and radiates toward the groin often points to the right kidney or ureter. Kidney stones are the classic culprit. A stone that gets stuck as it moves from the kidney down the narrow ureter produces sudden, severe, wave-like pain that many people describe as the worst they’ve ever experienced. It commonly hits the right flank and lower quadrant and can be accompanied by blood in the urine.⁷ Smaller stones often pass on their own with pain management and fluids, while larger ones may need medical intervention to break them up or remove them.

Kidney infections, known as pyelonephritis, are another major cause of right flank pain. These typically develop when a lower urinary tract infection, such as a bladder infection, travels upward to the kidney. The hallmark combination is flank pain, fever, and nausea.⁸ Unlike a kidney stone, a kidney infection is caused by bacteria and requires antibiotics. In rare cases, especially in people with poorly controlled diabetes, the infection can become severe enough that gas forms within the kidney tissue, a condition known as emphysematous pyelonephritis, which is a surgical emergency.⁹

Right-Sided Pelvic Pain in Women

In women, the right ovary and fallopian tube add another set of potential causes. Ovarian torsion, where the ovary twists on its blood supply, causes sudden and severe pelvic pain, typically on one side. Nausea and vomiting often follow. The biggest risk factor is having an ovarian cyst or mass that makes the ovary heavier and more prone to twisting.¹⁰ Ovarian torsion is a time-sensitive emergency because the twisted blood supply can cause the ovary to die if not corrected quickly, usually through surgery.

Ectopic pregnancy, where a fertilized egg implants outside the uterus (most often in a fallopian tube), is another life-threatening cause of one-sided pelvic or abdominal pain. When it ruptures, it can cause internal bleeding and even present with seemingly unrelated symptoms like chest pain or shoulder pain, which makes it tricky to diagnose.¹¹ Any woman of childbearing age with sudden right-sided abdominal or pelvic pain should have pregnancy ruled out as a routine step in the workup.

When the Pain Isn’t Coming From Where You Think

One of the more frustrating aspects of right-sided pain is that the source isn’t always in the abdomen. The body is unreliable at pinpointing where internal pain originates, and several conditions can create pain that feels like it’s in your right side when the actual problem is somewhere else entirely.

Pulmonary embolism, a blood clot that lodges in a lung artery, can cause sharp right-sided chest pain that worsens with breathing and is sometimes felt lower in the torso. A case involving a young man who developed right-sided chest pain after a leg fracture illustrates this: the clot traveled from his immobilized leg to his right lung, producing pain, shortness of breath, and coughing up blood-streaked sputum.¹² Right lower lobe pneumonia can produce a similar picture, with pain that feels more abdominal than chest-related, especially in younger patients.

Shingles is another surprising mimic. Before the characteristic blistering rash appears, shingles can cause burning or stabbing pain along one side of the body that closely resembles acute abdominal pain. Because the rash takes days to show up, patients sometimes undergo unnecessary workups for gallbladder disease or appendicitis before the real cause becomes clear.¹³

Abdominal wall problems can also fool you. Anterior cutaneous nerve entrapment syndrome happens when a small nerve running through the abdominal wall muscles gets compressed, creating a focal point of pain that feels deep and internal but is actually superficial. Doctors test for it using Carnett’s sign: if the pain gets worse when you tense your abdominal muscles (like doing a sit-up), it suggests the problem is in the wall rather than inside the abdomen.¹⁴ A local anesthetic injection at the tender spot often resolves the pain, confirming the diagnosis and providing treatment at the same time.

Vascular Causes Worth Knowing About

Right-sided colon ischemia, where blood flow to the right portion of the colon drops suddenly, is a less common but more dangerous cause of right-sided abdominal pain. Compared to ischemia affecting the left colon, right-sided involvement is more likely to be caused by a blockage in one of the large arteries feeding the gut rather than by the low-flow states that cause most left-sided cases.¹⁵ It also tends to have a worse outcome. The symptoms can be vague at first, with pain, bloating, and sometimes bloody diarrhea, and the condition is easily confused with a routine infection. Because an underlying large artery blockage may be the cause, doctors are advised to look specifically for vascular problems when right-sided colon ischemia is identified.¹⁶

Red Flags That Mean Go to the Emergency Room

Most episodes of right-sided pain turn out to be something manageable, but certain features signal that you should not wait it out. Get emergency care if you experience any of the following:

Sudden, severe pain: Pain that goes from zero to intense in minutes, especially with lightheadedness, could indicate a ruptured ectopic pregnancy, ovarian torsion, or a perforated organ.
Fever above 101°F (38.3°C) with pain: This combination suggests infection, whether of the gallbladder, kidney, appendix, or another structure. Infections that aren’t treated can progress to sepsis.
Pain with vomiting and inability to keep fluids down: This raises the urgency of appendicitis, bowel obstruction, or severe kidney stone.
Blood in urine or stool: Blood in the urine with flank pain suggests a kidney stone or infection. Blood in the stool with right-sided pain can indicate colon ischemia or another serious bowel problem.
Shortness of breath or chest pain: Right-sided chest pain with difficulty breathing raises concern for pulmonary embolism, especially after recent surgery, immobility, or a long flight.
Pain worsening over hours rather than improving: Appendicitis, in particular, tends to get steadily worse. Pain that comes and goes is generally less alarming than pain that only escalates.
Abdominal rigidity: If your abdominal muscles are involuntarily tense and the area is extremely tender to the touch, this can signal peritonitis, an infection of the abdominal lining that requires immediate treatment.

How Doctors Sort It Out

Because so many conditions can cause right-sided pain, imaging is often essential. Ultrasound is usually the first test ordered for upper right quadrant pain because it’s fast, radiation-free, and effective at identifying gallstones and cholecystitis. For detecting gallbladder problems specifically, ultrasound and CT scans perform about equally well.²

CT scans, however, pick up a wider range of problems and are better at catching conditions like appendicitis, where CT detected about 94% of cases compared to roughly 76% detected by ultrasound in one head-to-head study.² An important finding from research involving more than 2,800 emergency patients is that when ultrasound was done first for upper right quadrant pain and followed by CT, the CT scan revealed an acute problem that the ultrasound had missed in about a third of cases.¹⁷ That doesn’t mean everyone needs a CT, but it does explain why doctors sometimes order a scan after an ultrasound that looks normal, especially when the clinical picture doesn’t add up.

A practical approach that some hospitals follow is to start with ultrasound and move to CT only when the ultrasound is negative or unclear. This conditional strategy has been shown to miss only about 6% of urgent diagnoses, combining the safety advantage of starting without radiation with the thoroughness of CT when it’s truly needed.¹⁸

Pregnancy, Older Adults, and Other Special Situations

Pregnancy complicates the picture in several ways. The growing uterus physically shifts organs, so the appendix, for example, may sit higher than usual by the third trimester. This displacement can make appendicitis present with pain in a location that doesn’t match the textbook description, leading to delays in diagnosis. In rare cases, appendicitis in a pregnant woman has been mistaken for HELLP syndrome, a serious pregnancy complication involving the liver and blood cells.¹⁹ Because both conditions are dangerous, clinicians need to keep a broad list of possibilities when evaluating right-sided pain during pregnancy.

Older adults present their own diagnostic challenge. Pain perception tends to blunt with age, so a condition that would cause severe pain in a younger person may produce only mild discomfort in someone over 70. This means serious problems like mesenteric ischemia (loss of blood flow to the intestines) and even a leaking abdominal aortic aneurysm can be initially underestimated. Abdominal pain is one of the most common reasons older adults visit the emergency department, and the rate of misdiagnosis is higher in this group because the usual clinical clues are less reliable.²⁰

Right-Sided Pain That Persists After Gallbladder Surgery

Gallbladder removal is one of the most common surgeries performed, and most people recover completely. But a subset of patients continue to have upper right quadrant pain afterward, a situation broadly labeled post-cholecystectomy syndrome. The causes vary. About a third of these cases involve dysfunction of the sphincter of Oddi, a small muscular valve that controls bile flow into the intestine.²¹ Other common culprits include problems that were actually present before the surgery and mistakenly attributed to the gallbladder, such as peptic ulcers, acid reflux, chronic pancreatitis, or irritable bowel syndrome. Removal of the gallbladder also changes the way bile is delivered to the intestine, and these physiological shifts can themselves produce new symptoms in some people.²²

If you’ve had your gallbladder out and the pain has returned or never fully resolved, the takeaway is that a different source of the pain may have been there all along. Working through the other possible causes with your doctor, rather than assuming the surgery failed, is usually the most productive path forward.

Rare But Real Causes

A few uncommon conditions are worth mentioning because they tend to be diagnosed late, leading to unnecessary suffering. Amyand’s hernia is a rare type of inguinal hernia in which the appendix gets trapped within the hernia sac in the groin. This produces right groin pain and a visible bulge, and imaging may reveal the appendix sitting in an unexpected location.²³ It’s treated surgically.

Nerve entrapment in the abdominal wall, discussed earlier, is another condition that’s probably underdiagnosed. People can go through extensive and expensive workups looking for internal organ problems when the culprit is a pinched nerve in the muscle layer. The key distinguishing feature is that the pain gets worse with muscle contraction rather than better, and a local anesthetic injection can both confirm the diagnosis and relieve the pain. If you’ve had recurring right-sided abdominal pain with normal blood tests and imaging, it’s worth asking your doctor about this possibility.

1
PubMed. Imaging Evaluation for Acute Pain in the Right Upper Quadrant
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PubMed Central. Fever with abdominal pain and diabetes – Is it Emphysematous Pyelonephritis?
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PubMed Central. A review of ovary torsion
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PubMed Central. Shingles (Herpes Zoster) Mimicking Acute Abdomen
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PubMed Central. Anterior cutaneous nerve entrapment syndrome with pain present only during Carnett’s sign testing: a case report
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