Most abdominal masses come from an enlarged organ, a hernia pushing tissue through the abdominal wall, a hollow organ that is full or blocked, or a growth such as a cyst, fibroid, or tumor.
Location narrows the list quickly: upper right suggests the liver or gallbladder, upper left the spleen, lower middle a full bladder or a pregnant or fibroid uterus, and the lower sides a stool-filled colon. How it behaves matters too, since a hernia often bulges when you cough or stand and softens when you lie down, while a lipoma in the fat layer feels soft, rubbery, and movable. A pulsing mass near the navel in an older adult can be an aortic aneurysm and needs same-day assessment. Staying regular with fiber and fluids, emptying your bladder fully, and avoiding straining or heavy lifting with an untreated hernia all reduce the everyday causes. A clinician can usually sort this out with an exam plus an ultrasound or CT scan, so a new lump is worth an appointment rather than watchful waiting at home.
What happens next
Common questions
What causes Abdominal mass?
An abdominal mass is a lump or swelling felt in the belly, and the cause depends largely on where it sits. Common ones include a hernia at the navel, groin, or a past surgical scar, a stool-filled colon from constipation, a distended bladder, an enlarged liver or spleen, ovarian cysts, uterine fibroids, pregnancy, an abdominal aortic aneurysm, and less often a tumor. Soft, movable lumps just under the skin are often lipomas. Any new, growing, hard, or painful mass needs an in-person exam and usually imaging. Seek emergency care if a mass comes with severe pain, vomiting, fever, or will not push back in.