Pain in your lower right side has several possible causes, ranging from a pulled muscle to a condition that needs emergency care. The most important thing to sort out quickly is whether the pain is getting worse over time, because that pattern points toward causes like appendicitis that require urgent treatment. A dull ache that comes and goes, or pain tied to certain movements, is more likely muscular or digestive in origin.
Your lower right abdomen contains your appendix, the end of your large intestine, your right ureter (the tube connecting your kidney to your bladder), and layers of muscle. Any of these structures can generate pain, and each one produces a slightly different pattern you can learn to recognize.
Appendicitis: The First Thing to Rule Out
Appendicitis is the most urgent cause of lower right abdominal pain, and it’s the diagnosis doctors check for first. The classic pattern starts with vague pain around your belly button that migrates to a specific spot in your lower right abdomen over 12 to 24 hours. That spot, called McBurney’s point, sits about two inches along an imaginary line drawn from the bony point of your hip to your belly button, roughly one-third of the way across.
The pain of appendicitis typically gets steadily worse rather than coming and going. A hallmark feature is rebound tenderness: pressing on the sore area hurts, but releasing the pressure hurts even more. You may also notice that coughing or going over a speed bump sharpens the pain, because any jostling irritates the inflamed tissue. Nausea, vomiting, low-grade fever, and loss of appetite often accompany the pain. If the pain started mild and has been building over hours, that’s a pattern worth taking seriously.
For children, doctors typically start with an ultrasound to avoid radiation exposure. This approach has a reported sensitivity and specificity of 94%, and a CT scan can follow if the ultrasound results are unclear. Adults are more commonly evaluated with CT imaging for a definitive answer.
Kidney Stones
A stone moving through your right ureter can produce intense pain in your lower right side, but the character of the pain is different from appendicitis. Kidney stone pain tends to come in waves. You’ll feel severe cramping that builds, peaks, and then eases before starting again. The pain often radiates from your back or flank around toward your groin.
Urinary symptoms help distinguish a stone from other causes. You might notice pink, red, or brown urine, a burning sensation when you pee, or a persistent feeling that you need to urinate even when your bladder is nearly empty. Cloudy or foul-smelling urine can also appear. Nausea and vomiting are common during pain peaks. If you develop a fever and chills along with these symptoms, that suggests the stone may be causing an infection, which needs prompt treatment.
Muscle Strain and the Psoas
Not all lower right pain comes from an organ. A strained muscle in your abdomen or hip flexor can convincingly mimic internal problems. The psoas muscle runs deep along your spine and through your pelvis, and when it’s irritated, it produces pain in the lower abdomen that can feel like something is wrong inside.
The key difference is that muscle pain changes with position and movement. Psoas pain tends to worsen when you try to stand up straight, when you lift your thigh against resistance, or when you walk (sometimes causing a noticeable limp). It often improves when you curl up or sit with your hips flexed. If you can pinpoint an activity that triggered the pain, like heavy lifting, running, or an intense workout, a muscle strain becomes more likely. Doctors diagnose psoas problems partly through a process of elimination, ruling out organ-related causes first before settling on a musculoskeletal explanation.
Right-Sided Diverticulitis
Diverticulitis on the right side is less common than the left-sided version most people have heard of, but it produces pain in nearly the same location as appendicitis. It tends to affect people between ages 20 and 40, slightly older than the peak age group for appendicitis (10 to 19 years).
A few subtle differences set it apart. Right-sided diverticulitis comes on more gradually, with symptoms lasting longer before you seek care. Nausea, vomiting, and fever are less frequent than with appendicitis. The pain is often located slightly higher and more toward the side than McBurney’s point, and pressing on the area typically produces pain without the sharp rebound tenderness that appendicitis causes. In practice, the two conditions are difficult to tell apart without imaging, and many cases of right-sided diverticulitis are only identified after a patient goes in for suspected appendicitis.
What Doctors Check During the Exam
When you show up with lower right pain, the physical exam involves a specific set of maneuvers designed to narrow down the source. Understanding what the doctor is testing for can make the experience less confusing.
Pressing on your left lower abdomen and checking whether you feel pain on the right side tests for referred pain, a sign that points toward appendicitis. Having you lie on your left side while the doctor extends your right hip backward stretches the psoas muscle. If that reproduces your pain, the appendix (which sits near the psoas) may be inflamed, or the muscle itself may be the problem. Bending your right knee and rotating the hip inward tests a different muscle group and can reveal inflammation deeper in the pelvis.
These hands-on tests, combined with blood work and imaging, help doctors move from a broad list of possibilities to a specific diagnosis. No single test is definitive on its own, which is why the exam typically involves several of them in sequence.
Patterns That Need Emergency Care
Lower right abdominal pain is common and often resolves on its own, especially when it’s related to gas, constipation, or a mild muscle pull. But certain patterns signal something more serious:
- Severe pain that makes it hard to stand or walk
- Pain that started mild and is steadily getting worse over hours
- Fever or chills alongside the abdominal pain
- Blood in your urine or stool
- Vomiting blood or shortness of breath with the pain
- Pain that spreads upward toward your chest, neck, or shoulder
- Yellowing skin or eyes
If your pain doesn’t go away, keeps coming back, or matches any of these patterns, an emergency room visit is the right call. Severe pain in the lower right abdomen in particular warrants immediate evaluation, because conditions like appendicitis can progress to a rupture within 48 to 72 hours of symptom onset, and treatment is far simpler before that happens.