Low abdominal pain has dozens of possible causes, ranging from mild and temporary (trapped gas, a pulled muscle) to serious and time-sensitive (appendicitis, ectopic pregnancy). What’s causing yours depends largely on where exactly the pain is, how it feels, how quickly it came on, and your sex and age. Understanding these patterns can help you figure out what you’re dealing with and whether you need urgent care.
Right Side vs. Left Side Pain
The lower abdomen isn’t one uniform zone. Doctors divide it into right and left lower quadrants, and the location of your pain is one of the strongest initial clues to its cause.
Pain in the right lower quadrant is the classic location for appendicitis, the most common surgical emergency involving the abdomen. It typically starts as a vague ache around the belly button, then migrates to the lower right over several hours, becoming sharper and more localized. Tenderness at a specific spot about one-third of the way between the hip bone and the belly button is a hallmark sign, with roughly 87% sensitivity for identifying appendicitis when pinpointed precisely. Right-sided pain can also come from kidney stones passing through the right ureter, inflammatory bowel disease affecting the end of the small intestine, or colitis.
Left lower quadrant pain, especially in adults over 50, often points to diverticulitis, an infection or inflammation of small pouches that form along the colon wall. This pain tends to be constant, dull or cramping, and may come with fever, nausea, and changes in bowel habits. Kidney stones on the left side, colitis, and inflammatory bowel disease can also produce left-sided pain.
Causes Specific to Women
The pelvis houses the uterus, ovaries, and fallopian tubes, which means women have a significantly broader list of possible causes for low abdominal pain.
Ectopic pregnancy is the most dangerous. It occurs when a fertilized egg implants outside the uterus, usually in a fallopian tube. Before rupture, the pain is typically localized to one side due to the tube stretching. After rupture, it spreads across the entire lower abdomen as blood irritates the surrounding tissue. Any woman of reproductive age with low abdominal pain and a positive pregnancy test needs immediate evaluation. This is a life-threatening emergency.
Ovarian cysts are fluid-filled sacs on an ovary. Many come and go without symptoms, but when one ruptures, the leaking fluid irritates the abdominal lining and can cause sudden, sharp pain along with tenderness and bloating. Ovarian torsion, where an ovary twists on its blood supply, causes severe one-sided pain that comes on quickly and often triggers nausea and vomiting. It requires emergency treatment to save the ovary.
Endometriosis, where tissue similar to the uterine lining grows outside the uterus, causes chronic pelvic pain that often worsens around menstruation. Ruptured endometriomas (sometimes called “chocolate cysts” because of the dark blood they contain) can cause acute flare-ups. Pelvic inflammatory disease, an infection of the reproductive organs usually caused by sexually transmitted bacteria, produces low abdominal pain on both sides along with unusual discharge, fever, and pain during intercourse. Uterine fibroids, noncancerous growths in the uterine wall, can cause a persistent heaviness or pressure in the lower abdomen along with heavy periods.
Causes Specific to Men
Men experiencing low abdominal pain should consider a few conditions linked to the prostate and reproductive anatomy. Prostatitis, inflammation of the prostate gland, causes pain in the lower belly, groin, perineum (the area between the scrotum and rectum), and sometimes the lower back. It often comes with urinary symptoms: burning during urination, difficulty starting a stream, frequent urges to go (especially at night), and in some cases painful ejaculation. The acute bacterial form hits suddenly with fever, chills, and flu-like symptoms. A chronic form exists too, sometimes called chronic pelvic pain syndrome, which causes recurring pelvic discomfort even when no infection is found.
Inguinal hernias, where tissue pushes through a weak spot in the abdominal wall near the groin, are far more common in men. The pain typically worsens with coughing, bending, or lifting. Testicular torsion, where a testicle twists on its cord, causes severe scrotal pain that can radiate into the lower abdomen. Like ovarian torsion, it’s a surgical emergency.
Urinary Tract Causes
Bladder infections (cystitis) cause a dull, crampy discomfort in the lower abdomen along with frequent urination, burning when you pee, and sometimes cloudy or strong-smelling urine. They’re more common in women but can affect anyone. The pain is usually centered low and in the middle, just above the pubic bone.
Kidney stones produce a very different kind of pain. When a stone moves from the kidney into the ureter (the tube connecting the kidney to the bladder), it can cause intense, wave-like pain that starts in the flank and radiates down into the lower abdomen and groin. Many people describe it as the worst pain they’ve ever experienced. The pain comes in surges as the ureter spasms around the stone, and it’s often accompanied by blood in the urine, nausea, and an urgent need to urinate.
Digestive Causes
Irritable bowel syndrome (IBS) is one of the most common reasons for recurring low abdominal pain, affecting roughly 10 to 15 percent of adults. Pain typically fluctuates with bowel habits, improving after a bowel movement and worsening with stress or certain foods. IBS is classified as a functional disorder, meaning the gut looks structurally normal but doesn’t function properly. It can cause constipation, diarrhea, or alternating bouts of both.
Inflammatory bowel disease, which includes Crohn’s disease and ulcerative colitis, causes inflammation that damages the intestinal lining. Crohn’s often affects the lower right abdomen and produces pain along with diarrhea, weight loss, and fatigue. Ulcerative colitis tends to cause left-sided or diffuse lower pain with bloody diarrhea. Unlike IBS, these conditions cause visible tissue damage and require ongoing treatment.
Constipation itself is a surprisingly common and underappreciated cause of low abdominal pain. Stool buildup in the sigmoid colon (the S-shaped segment on the lower left) causes cramping and bloating that can feel alarming but resolves with a bowel movement. Trapped gas can produce sharp, localized pains that shift position and mimic more serious conditions.
Functional Abdominal Pain
Some people have persistent low abdominal pain with no identifiable structural or biochemical cause. This is called functional abdominal pain syndrome, and it’s a recognized medical diagnosis rather than a dismissal. The pain is continuous or nearly continuous, doesn’t consistently link to eating, bowel movements, or menstruation, and interferes with daily life. It’s thought to involve heightened pain signaling between the gut and the brain. Treatment usually combines strategies for managing chronic pain with approaches that address the nervous system’s role in amplifying discomfort.
When Low Abdominal Pain Is an Emergency
Certain patterns signal that you need emergency care, not a wait-and-see approach:
- Sudden, severe pain that makes it hard to stand, walk, or find a comfortable position
- Pain with uncontrollable vomiting or inability to keep any liquids down
- Complete inability to pass gas or have a bowel movement combined with worsening pain, which can indicate a bowel obstruction
- Pain with signs of internal bleeding like dizziness, rapid heartbeat, fainting, or pale skin
- Pain during pregnancy, particularly with vaginal bleeding
- Pain with high fever, which suggests infection that may be spreading
- Pain that feels different from previous episodes, especially if it’s more severe or comes with new symptoms
Previous abdominal surgery also raises the stakes. Scar tissue from past operations can cause bowel obstructions years later, so new pain in someone with surgical history warrants a lower threshold for seeking evaluation.
How Low Abdominal Pain Is Evaluated
When you go in for evaluation, doctors narrow the possibilities using your pain’s location, timing, and character combined with basic tests. A CT scan with contrast is the standard first imaging choice for most adults with concerning lower abdominal pain, particularly when appendicitis is suspected. For pregnant women, ultrasound or MRI is used instead to avoid radiation exposure. Blood work typically checks for signs of infection and, in women of reproductive age, a pregnancy test is one of the first things done regardless of whether pregnancy seems likely.
For chronic or recurring pain, the workup expands to include stool tests, colonoscopy, or pelvic ultrasound depending on the suspected cause. Many people with low abdominal pain never need imaging at all. If the pattern clearly fits something like constipation, IBS, or a mild bladder infection, diagnosis and treatment can happen based on symptoms alone.