The lower abdomen is the area between your belly button and your pubic bone, spanning the width of your torso. It sits below the upper abdominal organs like the stomach and liver and just above the pelvis. When people refer to pain or discomfort “in the lower abdomen,” this is the region they mean.
Exact Boundaries of the Lower Abdomen
The entire abdomen stretches from the diaphragm (the breathing muscle under your ribcage) down to the pelvic brim, which is the bony ridge where your hip bones curve inward. The lower abdomen occupies roughly the bottom third of that space. Its upper edge runs along an imaginary horizontal line at the level of your belly button. Its lower edge is formed by the inguinal ligaments, two bands of tissue that run diagonally from the bony points at the front of each hip down to the pubic bone in the center.
You can feel these landmarks on yourself. Place your fingers on the bony bump at the front of your hip (called the anterior superior iliac spine), then trace a line inward and downward toward the center of your groin. That diagonal crease where your thigh meets your torso follows the inguinal ligament closely. Everything above that line and below your navel is your lower abdomen.
How Doctors Divide It Into Sections
Healthcare providers use two mapping systems to describe locations within the abdomen more precisely. The simpler one divides the abdomen into four quadrants using two imaginary lines: one vertical down the midline and one horizontal across the belly button. The two bottom squares are the right lower quadrant (RLQ) and left lower quadrant (LLQ).
A more detailed system splits the abdomen into nine regions, like a tic-tac-toe grid. The three bottom boxes are the right inguinal region, the hypogastric (or suprapubic) region in the center, and the left inguinal region. Doctors use these grids to pinpoint where symptoms are happening, which helps narrow down the possible cause because different organs sit in each section.
Organs Inside the Lower Abdomen
Most of your small and large intestines live in the lower abdominal cavity, and they take up most of the space. On the right side, you’ll find the cecum (where the small intestine connects to the large intestine) and the appendix, a small finger-shaped pouch attached to the cecum. On the left side sit the lower portion of the descending colon and the sigmoid colon, which is the S-shaped segment that leads to the rectum.
The lower abdomen also shares space with pelvic organs. The bladder sits low and central, just behind the pubic bone. In women, the uterus, ovaries, and fallopian tubes are tucked into the bowl-shaped pelvic cavity directly beneath the lower abdominal wall. In men, the spermatic cords, which carry blood vessels, nerves, and the tubes that transport sperm, run from the lower abdomen through the inguinal canal down into the scrotum. The ureters, tubes that carry urine from the kidneys to the bladder, also pass through this region on both sides.
Your kidneys are actually positioned in the back of the abdominal cavity, but pain from a kidney problem can wrap around to the front and feel like it’s coming from the lower abdomen.
The Abdominal Wall That Protects It
Unlike the upper abdomen, which has the ribcage for extra protection, the lower abdomen relies entirely on layers of muscle and tissue. Three flat muscle layers stack on top of each other to form the abdominal wall. The outermost is the external oblique, followed by the internal oblique, and the deepest is the transversus abdominis. These muscles run in different directions, crossing over each other like plywood layers, which gives the wall its strength.
Down the center, the rectus abdominis muscles (the “six-pack” muscles) run vertically from the ribcage to the pubic bone. Together, these muscles do more than protect your organs. They stabilize your spine, support your posture, and generate the pressure needed for coughing, lifting, and bearing down. The lower portion of this muscular wall is also where inguinal hernias occur, when tissue pushes through a weak spot near the groin crease.
Why Lower Abdominal Pain Is So Common
Because the intestines dominate this region, digestive issues are the most frequent source of lower abdominal pain. Gas, constipation, diarrhea, food intolerances, and indigestion all tend to produce discomfort here. More serious intestinal conditions, including inflammation from infections or ulcers, also center in this area.
Location matters when identifying the source. Pain in the right lower quadrant raises concern about the appendix. Pain in the left lower quadrant often involves the sigmoid colon, the most common site for diverticulitis. Central lower abdominal pain may point to the bladder or, in women, the uterus or ovaries. Men can sometimes feel testicular pain that radiates upward into the lower abdomen because the nerves serving both areas overlap. This type of “referred pain,” where the discomfort shows up somewhere other than its actual source, is one reason lower abdominal pain can be tricky to pin down without further evaluation.