Lower abdominal pain most often comes from your intestines, which take up most of the space in your lower abdomen. Everyday digestive issues like gas, constipation, and indigestion are the most common culprits. But your bladder, appendix, and reproductive organs also sit in this region, so the cause depends heavily on exactly where the pain is, how it started, and what other symptoms you’re experiencing.
Digestive Causes Are the Most Common
Because your small and large intestines fill most of your lower abdominal cavity, they’re the most frequent source of pain there. Trapped gas can cause sharp, crampy pain that shifts around and then resolves once you pass it. Constipation creates a dull, persistent pressure that tends to sit in the lower left side, since that’s where your colon makes its final turn before the rectum. Diarrhea from a stomach bug or food intolerance often brings waves of cramping across the entire lower abdomen.
Two intestinal conditions that cause more significant pain are irritable bowel syndrome (IBS) and diverticulitis. Both produce lower abdominal tenderness and changes in bowel habits, which makes them easy to confuse with each other. The key difference: diverticulitis is an infection of small pouches that form in the colon wall, so it typically comes with fever and localized pain in the lower left abdomen. IBS is a chronic condition with recurring cramping that tends to improve after a bowel movement. Diverticulitis needs medical treatment, while IBS is managed over time with dietary and lifestyle changes.
Where the Pain Sits Matters
The location of your pain is one of the best clues to its cause.
Lower right side: Pain that’s specifically in the lower right is most concerning for appendicitis. This pain often starts as a vague ache near the belly button, then over a few hours migrates down and to the right, settling near the hip bone. It intensifies when you move, cough, or take deep breaths. Severe pain in this area warrants an emergency room visit.
Lower left side: This is the classic spot for diverticulitis, since the small pouches in the colon wall almost always develop in the lower left portion. Pain here can also come from constipation or, in women, from an ovarian cyst on the left side.
Center, below the belly button: Bladder infections often produce a feeling of pressure or discomfort right below the belly button. You’ll usually notice other urinary symptoms alongside it: a persistent urge to pee, burning during urination, passing only small amounts, or cloudy and strong-smelling urine. Pain in the center can also come from menstrual cramps or intestinal cramping.
Pain that wraps from the back: Your kidneys sit in the back of your abdominal cavity, but kidney stone pain can radiate around to the front and into the lower abdomen. Kidney stones tend to cause intense, wave-like pain that comes and goes, often with nausea. If that pain is accompanied by fever and chills, it may signal a kidney infection rather than a stone.
Causes Specific to Women
The uterus and ovaries sit in the lower pelvis, which means reproductive conditions frequently show up as lower abdominal pain. Menstrual cramps are the most obvious example, but several other conditions deserve attention.
Ovulation pain (sometimes called mittelschmerz) happens mid-cycle when an egg is released. It’s usually a brief, one-sided twinge that resolves within a day. Ovarian cysts, which are fluid-filled sacs on the ovaries, can cause a dull ache on one side that comes and goes. Most cysts resolve on their own, but a cyst that ruptures or twists causes sudden, sharp pain that needs immediate attention.
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus. It causes chronic pelvic pain that often worsens during periods, along with pain during sex and sometimes painful urination or bowel movements. Pelvic inflammatory disease (PID), an infection of the reproductive organs usually caused by sexually transmitted bacteria, brings lower abdominal pain along with unusual vaginal discharge, fever, and pain during sex.
An ectopic pregnancy, where a fertilized egg implants outside the uterus, causes lower abdominal pain that can become severe. If you’re of reproductive age and experiencing one-sided lower abdominal pain with vaginal bleeding or missed periods, this is a possibility that needs urgent evaluation.
Causes Specific to Men
Men can experience lower abdominal pain from inguinal hernias, where tissue pushes through a weak spot in the abdominal wall near the groin. This often feels like a dull ache that worsens with lifting, coughing, or straining. You may notice a visible bulge in the groin area.
Testicular problems can also register as abdominal pain because the nerves that supply the testicles travel through the abdomen. A testicular torsion (where the testicle twists on its blood supply) or infection in the testicle can produce pain that feels like it’s coming from the lower belly rather than the groin.
Bladder Infections and Urinary Causes
A bladder infection (cystitis) is one of the more common non-digestive causes of lower abdominal pain, especially in women. The hallmark symptoms are a strong, constant urge to urinate, a burning sensation when you do, and pelvic pressure below the belly button. You might also notice blood in your urine or urine that looks cloudy. Most bladder infections stay mild, but if you develop back or side pain, fever, chills, or vomiting, the infection may have spread to the kidneys.
How Appendicitis Pain Progresses
Appendicitis deserves its own focus because recognizing it early matters. It typically starts as a gnawing, aching pain around the belly button that feels different from normal stomach pain. Over the next several hours, the pain migrates to the lower right abdomen and becomes sharper and more constant. Moving around, coughing, or sneezing makes it worse.
Other symptoms often follow: loss of appetite, nausea or vomiting, a low-grade fever, abdominal swelling, and an inability to pass gas. The pain worsens steadily over hours, not days. If you’re experiencing this pattern, particularly the migration from the belly button to the lower right, don’t wait it out.
Signs You Need Emergency Care
Most lower abdominal pain comes from something temporary and manageable. But certain patterns signal something more serious:
- Pain so severe it interferes with normal functioning
- Pain with vomiting that won’t stop, especially if you can’t keep liquids down
- Complete inability to have a bowel movement combined with bloating and severe pain, which can indicate a bowel obstruction
- Pain that resembles something you’ve had before but is notably worse or different this time
- Fever with worsening abdominal pain
- Abdominal pain after recent surgery, which raises concern for complications like obstruction or infection
What to Expect at a Medical Visit
If your pain is persistent or concerning enough to see a provider, they’ll focus on where exactly it hurts, when it started, and what makes it better or worse. A physical exam with gentle pressure on different parts of your abdomen helps narrow down which organ is involved.
For imaging, a CT scan of the abdomen and pelvis is the most reliable tool for identifying serious causes. It picks up appendicitis about 94% of the time and diverticulitis about 81% of the time. Ultrasound is less sensitive overall but is the preferred first step for pregnant patients and is often used first in younger patients to avoid radiation exposure. For suspected bladder infections, a urine test is usually all that’s needed.
Many cases of lower abdominal pain, particularly those caused by gas, mild constipation, menstrual cramps, or a stomach bug, resolve on their own within hours to a couple of days. The pain patterns worth paying close attention to are those that are worsening steadily, accompanied by fever, or concentrated sharply on one side.