Lower stomach pain has dozens of possible causes, ranging from temporary digestive upset to conditions that need prompt treatment. Where exactly you feel the pain, how long it lasts, and what other symptoms come with it are the biggest clues to what’s going on. Most episodes are related to your digestive or urinary tract, though reproductive organs sit in this same region and are a common source of pain, especially in women.
Where the Pain Is Matters
Your lower abdomen stretches from your belly button down to your pubic bone, and it houses parts of your large and small intestines, your bladder, and (depending on your anatomy) your uterus, ovaries, or prostate. Pain on one side versus the center versus both sides can point in very different directions.
Pain in the lower right is the classic location for appendicitis. Pain in the lower left is more commonly tied to diverticulitis, a condition where small pouches in the colon wall become inflamed. Pain low and center, behind the pubic bone, often involves the bladder or uterus. And pain that shows up on just one side can signal a problem with a single ovary or kidney, like a cyst or a kidney stone, since these organs come in pairs and tend to cause trouble one at a time.
Digestive Causes
The most common reasons for lower abdominal pain are gastrointestinal. Constipation, gas, and stomach bugs account for a huge share of episodes that resolve on their own within a day or two. Beyond those, several chronic and acute conditions can be responsible.
Irritable Bowel Syndrome
IBS is one of the most frequent causes of recurring lower abdominal pain. It involves cramping, bloating, and changes in bowel habits (diarrhea, constipation, or both) without any visible damage to the intestines. Doctors generally consider IBS when symptoms have been present for at least six months and pain occurs at least one day per week for three months. The pain often improves or worsens around bowel movements. IBS is not dangerous, but it can significantly affect quality of life.
Diverticulitis
Diverticulitis happens when small pouches that form in the colon wall, most often on the lower left side, become infected or inflamed. It tends to cause steady pain in the lower left abdomen, sometimes with fever, nausea, and a change in bowel habits. It’s more common after age 40. The tricky part is that diverticulitis and IBS share symptoms like lower abdominal pain, tenderness, and irregular bowel patterns, so one is sometimes mistaken for the other. Diverticulitis typically comes on more suddenly, while IBS pain tends to be chronic and recurring over months or years.
Appendicitis
Appendicitis usually starts as a vague ache around the belly button that migrates to the lower right side over several hours and gets progressively worse. The most telling sign is sharp tenderness about two inches along an imaginary line drawn from your hip bone to your belly button. Another hallmark is rebound tenderness: pressing on that spot hurts, but releasing the pressure hurts even more. Appendicitis typically worsens quickly and requires surgery, so worsening right-sided pain that doesn’t let up warrants urgent medical attention.
Urinary Tract Causes
A urinary tract infection is one of the most common causes of pain or pressure low in the abdomen, centered behind the pubic bone. It usually comes with a burning sensation when you urinate, a frequent urge to go, and sometimes cloudy or strong-smelling urine. UTIs are far more common in women but can affect anyone.
Kidney stones typically cause pain on one side that can radiate from the back around to the lower abdomen and groin. The pain tends to come in intense waves rather than staying constant, and it’s often described as some of the worst pain people have experienced. You may also notice blood in your urine or feel nauseated.
Reproductive Causes in Women
The uterus, ovaries, and fallopian tubes all sit in the lower abdomen, making this region especially prone to pain tied to the menstrual cycle and reproductive health.
Menstrual Cramps and Ovulation Pain
Period cramps are the single most common cause of lower abdominal pain in women of reproductive age. They typically start just before or at the beginning of a period and last one to three days. Ovulation pain, sometimes called mittelschmerz, is a shorter, one-sided ache that occurs mid-cycle when an egg is released. It usually resolves within a few hours to a day.
Endometriosis
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus, often on the ovaries, fallopian tubes, or pelvic tissue. This tissue responds to hormonal changes each month, thickening and breaking down just like the uterine lining, but it has no way to leave the body. Over time, it irritates surrounding tissues and can form scar tissue and adhesions that bind organs together. The hallmark symptom is pelvic pain that goes well beyond normal menstrual cramping. Pain during sex, painful bowel movements or urination, lower back pain, bloating, fatigue, and difficulty getting pregnant are also common. Symptoms often worsen during periods but can occur at any point in the cycle.
Ovarian Cysts and Pelvic Inflammatory Disease
Ovarian cysts are fluid-filled sacs that form on or in an ovary. Most are small, cause no symptoms, and resolve on their own. Larger cysts can cause a dull ache or sharp pain on one side of the lower abdomen, especially if they twist or rupture. Pelvic inflammatory disease is an infection of the reproductive organs, usually caused by sexually transmitted bacteria. It can produce lower abdominal pain, unusual discharge, fever, and pain during sex. Left untreated, PID can lead to lasting damage, so persistent pelvic pain with these accompanying symptoms is worth getting checked.
Causes More Common in Men
Men can develop prostatitis, which is inflammation of the prostate gland. It causes pain in the lower belly, groin, or the area between the scrotum and rectum. Urinary symptoms are common: difficulty urinating, frequent urges, or a burning sensation. Some men also experience painful ejaculation. Chronic prostatitis can cause symptoms that come and go over weeks or months. Acute prostatitis tends to come on suddenly with more severe pain and sometimes fever.
Testicular problems, including torsion (twisting of the testicle), can also refer pain to the lower abdomen. Pain in the scrotum that radiates upward, especially if it comes on suddenly, is a medical emergency.
Signs You Need Urgent Care
Most lower abdominal pain isn’t an emergency, but certain symptoms signal that something serious may be happening. Get to a doctor or emergency room if you experience:
- Severe pain that doesn’t ease up or keeps getting worse over hours
- Fever and sweats alongside abdominal pain
- Blood in your stool, urine, or vomit
- Persistent vomiting, especially if you can’t keep fluids down
- Faintness or dizziness with abdominal pain
- Pain during pregnancy or unexpected vaginal bleeding
- Inability to pass gas or have a bowel movement, which may indicate a blockage
- Scrotal pain in men
Pain that spreads from your abdomen to your chest, neck, or shoulder also warrants immediate evaluation, as it can indicate a problem beyond the digestive tract.
What to Do at Home
For mild pain that doesn’t come with any of the red flags above, a few simple steps can help. Rest, stay hydrated, and avoid heavy or greasy foods. A heating pad on low over the painful area can ease cramping. If you feel ready to eat, start with bland foods like crackers, rice, bananas, or toast.
Over-the-counter antacids can help if the pain seems related to indigestion. For general pain relief, acetaminophen (Tylenol) is a safer first choice than ibuprofen or aspirin, which can irritate the stomach and potentially worsen some abdominal conditions. Avoid anti-inflammatory painkillers unless you’re confident the pain isn’t related to your stomach or intestines.
If the pain is mild but keeps coming back over weeks, that pattern itself is worth bringing up with a doctor. Chronic or recurring pain, even when it’s not severe, can point to conditions like IBS, endometriosis, or diverticular disease that benefit from a proper diagnosis. For lower abdominal pain, doctors typically start with a physical exam and blood work. If imaging is needed, a CT scan is the standard first choice for pain on the left or right side, while a pelvic ultrasound is preferred when a gynecologic cause is suspected or pregnancy is possible.