Lower Abdominal Pain: 9 Causes and When to Seek Emergency Care

Lower abdominal pain is a common, and at times distressing, symptom that most people will encounter in their lifetime. It can range from a mild, fleeting discomfort to a sharp, sudden, and alarming sensation. The ability to distinguish a benign ache from a sign of a serious medical condition can be critical. This article will provide an in-depth exploration of nine of the most likely causes of lower abdominal pain, detailing their symptoms and key identifiers, and will highlight crucial red flags that signal the need for emergency medical care.

To effectively understand the possible causes of pain in this region, it is helpful to first review the anatomy. The lower abdomen and pelvis, located just below the navel and extending down into the groin, house a complex arrangement of organs from multiple body systems. These include parts of the small and large intestine, specifically the colon, sigmoid colon, and cecum. The urinary tract is also located here, comprising the bladder and ureters. In people with female reproductive organs, the uterus, ovaries, and fallopian tubes are in this area, while men have the prostate and testes. Additionally, the pelvic and abdominal walls are composed of muscles and ligaments. Given this complex array of structures, pain in the lower abdomen can originate from the digestive, urinary, reproductive, or even musculoskeletal systems.

Appendicitis is a common and often acute condition involving the inflammation of the appendix, a small, finger-like pouch attached to the large intestine. It is an urgent medical condition that, if left untreated, can lead to a ruptured appendix and a life-threatening infection of the abdominal lining known as peritonitis. The onset of appendicitis pain is often very specific: it typically starts near the belly button (periumbilical) before migrating to the lower right side of the abdomen, a region known as the right iliac fossa. The pain becomes progressively sharper and more localized, often worsening with any movement, coughing, or even a light touch. This tenderness can be a key diagnostic sign, with doctors looking for “guarding” or “rebound tenderness.” Accompanying symptoms often include nausea, vomiting, and a loss of appetite, along with a low-grade fever. ^[2] Special considerations exist for certain groups; for instance, in women of reproductive age, appendicitis can sometimes be misdiagnosed as a gynecologic issue, while in pregnant women, the position of the appendix changes, making diagnosis more challenging. ^[3]

Diverticulitis is a condition most common in older individuals, resulting from the inflammation or infection of small, bulging pouches, or “diverticula,” that form in the colon wall. In Western populations, these pouches are most common in the sigmoid colon, which is located in the lower left abdomen. This is why diverticulitis often presents as a constant, aching pain in the lower left side. ^[5] The pain may be accompanied by a range of symptoms, including fever, chills, a bloated sensation, and a noticeable change in bowel habits, such as either constipation or diarrhea. In more severe or infected cases, blood may be present in the stool.

Problems affecting the urinary tract and kidneys can manifest as pain in the lower abdomen or groin. A Urinary Tract Infection (UTI), for example, is often characterized by pain or a burning sensation during urination, a frequent urge to urinate, and sometimes cloudy or bloody urine. Kidney stones, a type of renal colic, can cause a sudden, severe pain that originates in the back or flank and radiates down into the lower abdomen and groin. The pain from a kidney stone may also be accompanied by visible blood in the urine. A more serious kidney infection, known as pyelonephritis, can lead to flank pain along with a high fever, chills, and nausea. These conditions can often be distinguished from other causes of abdominal pain by the presence of these specific urinary symptoms.

In individuals with female reproductive organs, a significant number of lower abdominal pain causes are related to gynecologic conditions. These can range from common, cyclical pain to urgent medical emergencies. Pelvic Inflammatory Disease (PID) is an infection of the uterus and fallopian tubes that often presents with lower abdominal pain alongside symptoms such as abnormal vaginal discharge and tenderness of the cervix. ^[8] An Ectopic Pregnancy, a life-threatening condition, occurs when a fertilized egg implants outside the uterus, most often in a fallopian tube. It can cause sharp, one-sided lower abdominal pain and vaginal bleeding, and requires immediate medical attention if the tube ruptures. More common are Menstrual Cramps (dysmenorrhea), where pain is cyclical and directly related to a person’s period. Endometriosis is a chronic condition where tissue similar to the uterine lining grows outside the uterus, causing periodic and often severe pain, especially around menstruation. Conditions like Uterine Fibroids and Adenomyosis can also cause lower abdominal pain, often in conjunction with heavy bleeding and a feeling of fullness in the pelvic area.

Sometimes, the source of lower abdominal pain is an inflammatory or infectious process within the digestive system. Viral or bacterial enteritis and gastroenteritis can cause lower abdominal cramps, which are often accompanied by diarrhea and, in some cases, blood. Inflammatory Bowel Disease (IBD), which includes Crohn’s disease and Ulcerative Colitis, is a chronic condition causing recurring pain, changes in bowel habits, and weight loss. While often confused with it, Irritable Bowel Syndrome (IBS) is a separate functional disorder. IBS pain is typically crampy and is often relieved by a bowel movement; it is associated with stress and diet but does not typically cause fever or blood in the stool and is not dangerous, though it can significantly impact quality of life.

Ovarian cysts are common and often harmless; most are small and resolve on their own.26 However, if a cyst becomes large or ruptures, it can cause sudden, sharp lower abdominal pain and potentially internal bleeding. ^[9] A much more serious condition is Ovarian Torsion, which occurs when an ovary twists on its supporting ligaments, cutting off its blood supply. Ovarian torsion is a true surgical emergency that causes sudden, severe pain, often accompanied by nausea and vomiting, and requires urgent intervention to save the ovary. ^[10]

These three common, non-life-threatening conditions can cause significant discomfort in the lower abdomen. Gas and bloating can lead to crampy, sharp pains that often improve after passing gas. Constipation is characterized by infrequent bowel movements and hard stools, which can cause a feeling of a distended abdomen and general discomfort. As mentioned earlier, Irritable Bowel Syndrome (IBS) is a functional disorder whose pain is often linked to bowel movements and changes in bowel habits. These conditions are not typically associated with red flags like fever or blood and are generally not dangerous, though they can be very uncomfortable.

In some cases, the source of the pain is not an internal organ but rather a structural or musculoskeletal issue in the abdominal wall. An Inguinal Hernia or Femoral Hernia can cause a visible bulge in the groin area and pain that is worsened by physical activity, heavy lifting, or straining. Other causes include abdominal wall strain or muscle injuries that result from overuse, lifting heavy objects, or trauma. A less common but important cause is a rectus sheath hematoma, which is a collection of blood in the abdominal wall muscles. This can occur after trauma or in individuals on blood-thinning medications.

While not common, certain life-threatening conditions can cause severe lower abdominal pain. Peritonitis is a widespread inflammation of the peritoneum, the membrane lining the abdomen, often caused by a perforation of the bowel or appendix. The pain becomes severe, and the abdomen feels rigid and tender. Mesenteric ischemia, a vascular emergency, occurs when the blood supply to the intestine is compromised, leading to very severe pain that is often out of proportion to the physical exam findings. Rare conditions like omental infarction or torsion can also cause sudden pain that mimics more common conditions like appendicitis or diverticulitis. ^[11] A ruptured ectopic pregnancy is also a vascular emergency that can lead to life-threatening internal bleeding.

Because so many of these conditions cause overlapping symptoms, doctors use a combination of tools to arrive at an accurate diagnosis. The initial step is a detailed patient history, where the provider asks about the timing, location, and nature of the pain, its relation to eating or menstrual cycles, and any accompanying urinary or vaginal symptoms. A thorough physical exam is also critical, with the doctor checking for specific signs like tenderness, guarding, rebound tenderness, and classic signs like Rovsing’s or the psoas sign, which are highly suggestive of appendicitis.

Laboratory tests are a standard part of the workup; these may include a complete blood count to check for an elevated white blood cell count (leukocytosis), a key sign of infection. For women of childbearing age, a pregnancy test is a crucial early step, and urinalysis can help identify urinary tract issues. ^[13] Imaging studies, such as an ultrasound, are particularly useful for diagnosing gynecologic causes like ovarian cysts or torsion. For conditions like appendicitis or diverticulitis, a CT scan is often the imaging modality of choice. For example, a study comparing PID versus appendicitis found that an appendiceal diameter of 7 mm or greater on a CT scan, along with other CT features, could distinguish between the two conditions with high accuracy (around 98%) in women of childbearing age. ^[14] Physical signs like involuntary guarding and rebound tenderness are also more common in appendicitis than in many gynecologic causes.

While many causes of lower abdominal pain are not immediate emergencies, certain red-flag symptoms should prompt you to seek emergency medical care immediately. If you experience a sudden onset of severe pain, often described as “like nothing before”, or pain that is rapidly getting worse, you should not hesitate to go to the emergency room. ^[16] Other critical signs include abdominal rigidity or distension, where the belly feels very hard and is extremely tender to the touch. The presence of fever and chills alongside the pain is another red flag, as it can be a sign of a serious infection. ^[18] Any instance of blood in your stool, vomit, or urine, or vaginal bleeding if you are pregnant, requires immediate evaluation. ^[16] Signs of a bowel obstruction, such as an inability to pass stool or gas accompanied by severe, crampy pain, also warrant an emergency visit. ^[19] Furthermore, if you exhibit signs of shock, such as dizziness, fainting, a rapid or weak pulse, or very low blood pressure, this is a life-threatening emergency. Lastly, any pain that worsens despite rest, persists for more than a few days without improvement, or occurs during pregnancy should be checked by a medical professional. When in doubt, it is always safer to get checked.

Lower abdominal pain has a wide range of causes; some are harmless and self-limiting, such as gas or menstrual cramps, while others, like appendicitis, a ruptured ectopic pregnancy, or ovarian torsion, require urgent medical attention. The key to a proper diagnosis lies in paying close attention to the details: the location of the pain, how it began, what triggers it, and what other symptoms accompany it (e.g., fever, vomiting, bleeding, or changes in urinary or vaginal health). Do not rely solely on home remedies if you have any of the red-flag symptoms mentioned, as an early diagnosis can be the difference between a simple treatment and a life-threatening complication. Always provide your healthcare provider with a complete history, including your menstrual cycle, any possibility of pregnancy, and a history of similar episodes.