Pain in your lower right side has several possible causes, ranging from a pulled muscle to a condition that needs emergency care. The most common concern is appendicitis, but the lower right abdomen also houses parts of the intestine, the right kidney and ureter, and in women, the right ovary and fallopian tube. Where exactly the pain is, how it started, and what other symptoms you have all help narrow down what’s going on.
Appendicitis: The Most Common Concern
Appendicitis is the first thing most people (and most doctors) think of with lower right pain, and for good reason. The appendix sits in the lower right quadrant of your abdomen, and when it becomes inflamed, it produces a very recognizable pain pattern. It typically starts as a vague ache around your belly button, then over 12 to 24 hours migrates down and to the right, settling at a spot roughly halfway between your belly button and the bony point of your right hip. This spot, called McBurney’s point, is the classic location of appendicitis tenderness.
The pain usually gets steadily worse rather than better. It may sharpen when you walk, cough, or go over a bump in the car. Nausea, vomiting, loss of appetite, and a low-grade fever often accompany it. If your pain follows this pattern, especially if it’s been building over several hours, treat it as urgent. A ruptured appendix can cause a serious abdominal infection.
Kidney Stones
A stone moving through your right kidney or ureter can cause intense pain in your lower right side, though it often starts higher, in the flank between your lower ribs and hip. The pain tends to radiate downward toward your groin or lower belly. Unlike the steady worsening of appendicitis, kidney stone pain typically comes in waves lasting 20 to 60 minutes, with the worst intensity hitting one to two hours after it begins. Between waves you might feel a dull, constant ache.
The giveaway symptoms are urinary: pain when you pee, blood in your urine (which may look pink, red, or brown), cloudy or foul-smelling urine, or peeing more frequently than usual. Nausea and vomiting are common during the worst waves of pain. Fever and chills alongside kidney stone symptoms suggest a possible infection, which needs prompt medical attention.
Inguinal Hernia
An inguinal hernia happens when tissue pushes through a weak spot in your lower abdominal wall, creating a bulge in the groin area. It’s more common in men but can affect anyone. The hallmark is a visible or palpable bulge between your lower abdomen and thigh, along with feelings of discomfort, heaviness, or burning in the groin. The pain gets worse when you strain, lift something heavy, cough, or stand for a long time, and improves when you rest or lie down.
Most inguinal hernias aren’t emergencies, but if the bulge becomes firm, very painful, and won’t push back in, the tissue may be trapped (strangulated), which cuts off blood supply and requires immediate surgery.
Muscle and Soft Tissue Pain
Not all lower right pain comes from an organ. The psoas muscle runs deep through your pelvis and hip, and when it’s strained or inflamed, it can mimic pain from internal organs convincingly enough that it’s frequently misdiagnosed. Psoas pain typically worsens with certain movements, especially trying to stand up straight, walking, or lifting your leg. The pain may radiate down your leg and can be severe enough to make you limp.
A strained abdominal muscle can also cause localized lower right pain, particularly after exercise, heavy lifting, or an awkward movement. The key distinction is that muscle pain usually reproduces when you tense or stretch the area, while organ pain tends to be constant or comes in waves regardless of body position.
Digestive Conditions
Crohn’s disease most commonly affects the end of the small intestine, which sits in the lower right abdomen. This is why Crohn’s flares often produce cramping pain on the right side, along with diarrhea, fatigue, reduced appetite, weight loss, and sometimes blood in the stool. If you’ve been having recurring bouts of lower right pain paired with ongoing digestive symptoms, this is worth discussing with your doctor.
Other intestinal causes include infections, trapped gas, or inflammation of pouches in the intestinal wall. These tend to come with more obvious digestive symptoms like bloating, changes in bowel habits, or diarrhea.
Gynecological Causes in Women
The right ovary and fallopian tube sit in the lower right pelvis, so several reproductive conditions can produce pain in this area. An ovarian cyst that ruptures or twists (torsion) causes sudden, sharp pain, sometimes with nausea. Ovarian torsion is an emergency because it cuts off blood flow to the ovary.
Ectopic pregnancy, where a fertilized egg implants outside the uterus (usually in a fallopian tube), is a serious cause of one-sided lower pain in women of reproductive age. Early signs include light vaginal bleeding and pelvic pain. If the ectopic pregnancy ruptures, symptoms escalate to severe abdominal pain, shoulder pain, extreme lightheadedness, or fainting. If you could be pregnant and develop these symptoms, seek emergency care immediately.
How Doctors Figure Out the Cause
When you go in for lower right pain, expect a physical exam where the doctor presses on specific areas of your abdomen to check for tenderness, guarding (involuntary muscle tightening), or a palpable mass. They’ll likely ask when the pain started, whether it’s constant or comes and goes, and what makes it better or worse.
For imaging, CT scans are the recommended first choice for evaluating lower right abdominal pain. CT catches appendicitis with about 91% accuracy, compared to about 78% for ultrasound. However, doctors sometimes start with ultrasound for younger patients, children, or pregnant women to avoid radiation exposure, reserving CT for cases where ultrasound results are unclear. Blood work and a urine sample help rule out infection, kidney stones, or pregnancy.
Signs You Need Emergency Care
Some combinations of symptoms signal that you should get to an emergency room rather than waiting for a scheduled appointment:
- Severe or worsening pain that started mild and keeps escalating over hours
- Fever or chills alongside the pain
- Vomiting blood or shortness of breath
- Blood in your urine or stool
- Pain spreading upward toward your chest, neck, or shoulder
- Extreme lightheadedness or fainting
- Yellowing skin or eyes
Lower right pain that comes on suddenly and is severe from the start, or pain that started mild but has been steadily building for hours, generally warrants same-day evaluation. Even if the cause turns out to be something manageable, the lower right quadrant houses enough critical structures that it’s worth getting checked rather than waiting it out.