Right Side Stomach Pain: What Could Be Causing It?

Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician, Doctor Bangkok. Last reviewed: August 2026

You are two days into a Bangkok trip, or six months into expat life, and there is pain on the right side of your abdomen that you cannot explain. You have Googled it. Now you are somewhere between "probably nothing" and full panic. The truth is usually between those two, but the only way to know is to get it checked.

The right side of your abdomen is busy. Upper right is your liver, gallbladder, and part of your stomach. Lower right is your appendix, the start of your large bowel, and, in women, the right ovary. Pain in either zone can come from those organs directly, or be referred from somewhere else entirely. Location is your first clue.

Upper Right vs. Lower Right: Why the Location Matters

Upper right pain and lower right pain are not the same problem, and they point to different organs.

Upper right pain, especially after eating, often involves the gallbladder or liver. It can be dull and heavy, or sharp and cramping. Lower right pain, especially if it started near the belly button and moved down, is the classic pattern for appendicitis. That distinction alone helps narrow things down before a single test is run.

Pain that wraps around to your back or flank points more toward the kidney. Pain that comes in waves with urinary symptoms is usually a kidney stone. Pain that shifts when you change position is often bowel-related.

Common Causes of Right Side Stomach Pain

Gallstones and Gallbladder Pain

Gallbladder pain is one of the most common things I see in patients with right-side stomach pain, particularly upper right. It usually comes on after a fatty meal and can last anywhere from thirty minutes to several hours. Some patients describe pressure. Others say it feels like something squeezing them under the ribs.

One pattern worth knowing: pain that moves up to the right shoulder. If pressing under your right rib cage while taking a deep breath makes you wince and stop, that is a sign we take seriously. Gallstones can be confirmed quickly with an abdominal ultrasound. If you have had repeated episodes after meals, do not keep putting it off.

Appendicitis

Appendicitis usually starts as a vague ache around the belly button. Over hours, it moves to the lower right and becomes sharper and constant. Nausea, loss of appetite, and a low-grade fever often come with it.

The key word is constant. Crampy pain that comes and goes is less likely to be appendicitis. Pain that is there all the time, that gets worse when you press and release the lower right abdomen, that worsens when you walk or cough, that is the pattern that needs fast action.

Appendicitis is a surgical emergency. If this fits, do not take painkillers and hope it passes. Get assessed now.

Kidney Stones and Kidney Infection

Kidney pain tends to sit in the flank, the area between your lower ribs and your hip, and can radiate forward to the groin. Kidney stones cause intense, wave-like pain. A kidney infection gives a deeper, constant ache with fever, chills, and tenderness when pressing the back just below the ribs.

Burning or frequent urination alongside flank pain makes the picture fairly clear. A urine test at the clinic confirms it fast.

Liver and Hepatitis

A tender, heavy feeling in the upper right abdomen can come from the liver. Viral hepatitis and alcohol-related liver inflammation both cause this. Yellowing of the skin or eyes, dark urine, and fatigue alongside upper right pain should always prompt a liver function blood test. Hepatitis A is still seen in Bangkok through contaminated food and water.

Bangkok-Specific Causes Expats and Tourists Often Miss

This is the part most Western health websites skip, and it matters more here than anywhere else.

Dengue fever can cause significant upper right abdominal pain. The liver gets inflamed, and patients often feel tender in the upper right. If you have fever, body aches, and right-side stomach pain in Bangkok, dengue needs to be ruled out. A dengue NS1 blood test is quick and straightforward. Missing dengue is a real risk if your clinic is not thinking about it.

Intestinal parasites, including Giardia and other organisms picked up through food and water, can cause cramping that sits on the right side. Patients often assume it is a stomach bug and wait it out. If you have had loose stools, bloating, and right-side pain for more than a week after eating street food or drinking tap water, a stool test is worth doing.

Typhoid is less common but still seen here. Fever that builds over several days, abdominal discomfort, and altered bowel habits in someone who has eaten at high-risk food stalls is enough reason to test.

Right-side stomach pain after street food in Bangkok is often traveller’s diarrhoea, which causes crampy discomfort that can sit anywhere in the abdomen. Crampy and colicky is different from constant and localised. If it is constant and getting worse, it needs assessment regardless of what you ate yesterday.

Less Common Causes Worth Knowing

Right-sided diverticulitis is something most patients have never heard of. Diverticular disease is usually associated with the left side, but a right-sided version exists and is actually more common in people of Asian descent. It can mimic appendicitis closely enough to reach surgery before the correct diagnosis is made.

Pleuritic pain is another one people miss. Inflammation around the right lung can cause sharp pain in the right side of the chest or upper abdomen that worsens with breathing. I always ask: does your pain change when you breathe in deeply? A right-sided pneumonia can produce the same effect.

In women, an ovarian cyst or ectopic pregnancy on the right side can feel identical to appendicitis. A positive pregnancy test changes the entire picture. If there is any possibility of pregnancy and you have lower right pain, say so immediately.

Red Flag Symptoms: When to Get Help Now

Some symptoms mean this cannot wait.

Severe pain that came on suddenly and is not easing, a rigid or board-like abdomen, pain with high fever and chills, vomiting you cannot control, lower right pain in pregnancy with any bleeding, or fainting alongside abdominal pain. These need emergency care now, not a wait-and-see approach.

Peritonitis, meaning infection spreading inside the abdominal cavity, is life-threatening. It usually follows untreated appendicitis or a bowel perforation. The abdomen becomes extremely tender and rigid. That is an emergency room situation.

What Happens When You Come In

At Doctor Bangkok, a consultation for right-side stomach pain starts with a physical exam. I press on specific areas of the abdomen, check for rebound tenderness, listen to bowel sounds, and assess the gallbladder. This takes a few minutes and gives a lot of information before any test is ordered.

From there, I typically run a full blood count to check for infection or inflammation, a CRP for inflammation, and a urine test if the kidney could be involved. If the upper right is tender, liver function tests go in. If you have a fever in Bangkok, a dengue NS1 antigen test is added. An abdominal ultrasound can be done the same visit and picks up gallstones, liver changes, free fluid, and ovarian cysts clearly.

The exam plus targeted tests usually gives a clear answer within a few hours. You leave knowing what is going on.

Getting Assessed in Bangkok

If you are reading this from your hotel room or between BTS stops and are not sure whether to come in, here is the honest answer: right-side pain that has been there for more than a few hours and is not improving should be assessed.

Doctor Bangkok is a walk-in clinic in central Bangkok, BTS accessible, with English-speaking physicians. No appointment needed. If you cannot get to the clinic, we offer physician-led hotel visits across central Bangkok, around the clock. The doctor arrives with a full medical kit, can arrange blood tests, prescribe on-site, and give IV fluids if needed. If your situation needs a hospital, we will tell you clearly and help you get there.

You do not have to figure this out alone in an unfamiliar city.