Pain in the lower right abdomen has a wide range of causes, from a pulled muscle to a surgical emergency like appendicitis. The location narrows things down considerably compared to general abdominal pain, because several organs sit in or near that quadrant: the appendix, the end of the small intestine, the right ovary and fallopian tube, the right ureter, and part of the colon. What the pain feels like, how it started, and what other symptoms accompany it are the key details that point toward a specific cause.
Appendicitis
Appendicitis is the most well-known cause of lower right abdominal pain and the one most people worry about first. It follows a distinctive pattern: pain typically starts around the belly button, hovers or comes and goes for several hours, then intensifies and shifts to the lower right side. Nausea and vomiting often develop during this transition. The classic tender spot, called McBurney’s point, sits about two inches along an imaginary line drawn from the bony projection near your hip toward your belly button, roughly one-third of the way along that line.
Not everyone follows this textbook progression. Some people have an appendix positioned slightly differently, which can shift the pain. In young children and pregnant women, the symptoms can be vague enough to delay diagnosis. The hallmark of a worsening situation is rebound tenderness, where the pain spikes when you press on the area and then release. If the abdominal muscles involuntarily tighten when touched (a sign called guarding), that suggests the lining of the abdominal cavity has become irritated or infected, a condition called peritonitis that requires urgent treatment.
CT scans are the most reliable tool for diagnosing appendicitis, with sensitivity of 98.9% and specificity of 97.2%. Ultrasound is equally sensitive at 98.5% but far less specific at 54.2%, meaning it catches most cases but produces more false alarms. Ultrasound is often the first choice for children and pregnant women to avoid radiation exposure, with CT reserved for unclear results.
Ovarian Cysts and Ectopic Pregnancy
In women, the right ovary is a common source of lower right abdominal pain. Ovarian cysts form during the menstrual cycle and usually resolve on their own, but a cyst that ruptures or grows large can cause sharp, sudden pain on the affected side. If the ovary twists on its blood supply (ovarian torsion), the pain is severe and comes on abruptly, often with nausea and vomiting. Torsion cuts off blood flow and needs emergency treatment to save the ovary.
An ectopic pregnancy, where a fertilized egg implants in the fallopian tube instead of the uterus, produces early warning signs of light vaginal bleeding and pelvic pain. If the tube ruptures, the situation becomes life-threatening. Warning signs of a rupture include extreme lightheadedness, fainting, shoulder pain (caused by blood irritating the diaphragm), and an unusual urge to have a bowel movement. Any combination of missed period, pelvic pain, and vaginal bleeding warrants immediate evaluation.
Kidney Stones
A stone that forms in the right kidney and moves into the ureter (the tube connecting the kidney to the bladder) can produce intense pain that radiates from the back or flank down into the lower right abdomen and groin. This pain often comes in waves, building to a peak and then easing before returning. It’s frequently described as one of the most severe pains people experience. You may also notice blood-tinged urine, frequent urination, or nausea. The pain location shifts as the stone moves through the ureter, which is why it can start in the back and gradually migrate lower.
Crohn’s Disease
Crohn’s disease, a chronic inflammatory bowel condition, has a strong tendency to affect the end of the small intestine, known as the terminal ileum, which sits in the lower right abdomen. The ileum is inflamed in roughly 80% of Crohn’s cases. About one-third of cases involve the ileum alone, and another third involve both the ileum and the right side of the colon.
During flares, the pain can range from crampy and intermittent to intense and constant, often accompanied by diarrhea, fever, and dehydration. If chronic inflammation causes narrowing of the intestine, you may experience cramping after meals, bloating, and vomiting as food struggles to pass through. Some people with Crohn’s initially present with symptoms so similar to appendicitis that the correct diagnosis only becomes clear during surgery or imaging.
Right-Sided Diverticulitis
Most people associate diverticulitis with pain on the left side of the abdomen, and in Western populations that’s usually accurate. But diverticulitis can also develop on the right side, particularly in people of Asian descent. Right-sided and cecal diverticulitis accounts for up to 75% of diverticulitis cases in Asian populations. Because the cecum and ascending colon sit in the lower right quadrant, this form of diverticulitis produces pain that closely mimics appendicitis, making imaging important for getting the right diagnosis.
Inguinal Hernia
An inguinal hernia occurs when tissue, usually part of the intestine, pushes through a weak spot in the abdominal wall near the groin. The most obvious sign is a bulge on one side of the pubic bone that becomes more prominent when you stand up, cough, or strain. The pain tends to be a burning or aching sensation at the bulge site, worsening with physical exertion, bending, or lifting heavy objects. In men, the protruding tissue can descend into the scrotum, causing pain and swelling around the testicle. Most inguinal hernias aren’t immediately dangerous, but a hernia that becomes trapped (incarcerated) and loses its blood supply requires emergency surgery.
Mesenteric Adenitis
In children especially, swollen lymph nodes in the abdomen can cause lower right pain that looks and feels remarkably like appendicitis. This condition, called mesenteric adenitis, typically follows a viral upper respiratory infection or gastroenteritis. The lymph nodes near the intestine become inflamed, producing tenderness in the same location as the appendix. Unlike appendicitis, mesenteric adenitis usually resolves on its own. Ultrasound can help distinguish between the two by revealing clusters of enlarged lymph nodes rather than an inflamed appendix. Standard blood tests alone often can’t reliably tell them apart, which is why imaging plays an important role.
Testicular Torsion
In boys and young men, testicular torsion can present with abdominal pain before any obvious scrotal symptoms appear. The testicle twists on its spermatic cord, cutting off blood flow, and the pain can radiate upward into the lower abdomen. Because the initial complaint may be belly pain rather than testicular pain, torsion is sometimes missed early on. This is a time-sensitive emergency: the testicle can usually be saved if treated quickly, but delayed treatment risks permanent damage from blocked blood flow.
Muscle Strain and Other Common Causes
Not every case of lower right abdominal pain signals an organ problem. A strained abdominal muscle from exercise, heavy lifting, or even vigorous coughing can produce localized pain that worsens with movement. Constipation and trapped gas can also cause surprisingly sharp discomfort in the lower right quadrant, particularly if stool is building up in the cecum. These causes tend to have a clear connection to activity or dietary changes, and the pain usually improves with rest, movement, or passing gas.
How to Read the Warning Signs
The pace and pattern of your pain offer important clues. Pain that starts suddenly and is severe from the onset points toward rupture (of a cyst, ectopic pregnancy, or appendix), torsion, or a passing kidney stone. Pain that builds gradually over 12 to 24 hours and settles into one spot is more typical of appendicitis or diverticulitis. Chronic or recurring pain that flares with meals or stress suggests Crohn’s disease or another inflammatory condition.
Certain combinations of symptoms raise the urgency. Fever with worsening, localized pain suggests infection or inflammation that may need surgical attention. Vaginal bleeding with pelvic pain in a woman of reproductive age raises concern for ectopic pregnancy. Pain with an abdominal bulge that you can’t push back in suggests a trapped hernia. In any of these scenarios, the safest course is prompt medical evaluation rather than waiting to see if things improve.