A lump on the left side of the abdomen can arise from various structures, ranging from superficial layers of the abdominal wall to deeper internal organs. While many lumps are benign and represent minor issues, a palpable mass in this area should never be ignored. The abdomen houses many complex systems, and the cause of a lump can be difficult to pinpoint without professional medical assessment. This information is purely educational and is not a substitute for a thorough examination by a healthcare provider.
Lumps Originating in the Abdominal Wall
Many lumps found on the left side of the abdomen are superficial, meaning they originate from the skin, fat, or muscle layers. These masses are generally easier to feel and often move slightly when pressed. The most common cause is a hernia, which occurs when internal tissue pushes through a weak spot in the muscle or surrounding fascia.
On the left side, hernias like a Spigelian hernia or an incisional hernia (through an old surgical scar) can present as a noticeable bulge. The lump may become more prominent when coughing or straining, and might disappear when lying down. A hematoma, a collection of blood caused by trauma or muscle strain, can also form a lump within the abdominal wall.
Other superficial growths include lipomas, which are benign masses of fatty tissue beneath the skin. A lipoma usually feels soft, doughy, and rubbery. Cysts, enclosed sacs filled with fluid, can also develop under the skin. These masses are typically painless unless they become infected, which can lead to an abscess.
Digestive Tract and Bowel-Related Causes
The left side of the abdomen is home to the descending and sigmoid colon, making bowel-related issues a frequent source of a palpable mass. Severe constipation or a fecal impaction can result in a hard, sometimes movable, mass representing a buildup of hardened stool within the colon. This type of lump is often accompanied by bloating, abdominal discomfort, and difficulty passing a bowel movement.
Inflammation in the colon can also manifest as a lump due to the thickening of the bowel wall. Diverticulitis, where small pouches in the colon become inflamed or infected, commonly causes pain and tenderness in the lower left abdomen. In severe cases, the inflammation or an abscess can create a distinct, tender mass.
Inflammatory Bowel Diseases (IBD) like Crohn’s disease may cause chronic inflammation. This can lead to localized thickening of the intestinal wall, strictures, or an abdominal abscess, all of which can be felt as a firm mass. These masses are often associated with other digestive symptoms, including changes in bowel habits, nausea, vomiting, or fever.
Internal Organ Enlargement or Masses
Some of the more serious potential causes of a lump on the left side involve deep, solid organs located in the upper left quadrant of the abdomen. The spleen, normally tucked under the left rib cage, is not usually palpable in adults. If it becomes enlarged (splenomegaly), it can be felt as a mass below the ribs.
Splenomegaly can be caused by various underlying illnesses, including infections like mononucleosis, liver disease such as cirrhosis, or certain blood cancers. An enlarged spleen may also cause pain that can radiate to the left shoulder, as well as a feeling of fullness after eating. A large mass originating from the left kidney can sometimes be felt in the front of the abdomen.
Kidney masses can be benign, such as a fluid-filled cyst or a non-cancerous tumor, or they can be malignant. Symptoms associated with a kidney mass may include flank pain, blood in the urine, or unexplained weight loss. A potentially life-threatening cause is an abdominal aortic aneurysm (AAA), an abnormal bulge in the large artery. A large AAA, especially one that is leaking, may be felt as a deeply pulsating mass, requiring immediate emergency medical attention.
Seeking a Professional Diagnosis
Any unexplained lump on the left side of the abdomen warrants prompt medical evaluation due to the wide range of potential causes. A healthcare provider will perform a thorough physical examination, palpating the area to assess the mass’s size, consistency, and whether it is movable or pulsating.
To determine the precise cause, a doctor may order diagnostic tools such as blood tests, an ultrasound, or a computed tomography (CT) scan. These imaging tests provide detailed pictures of internal structures, helping to differentiate between a superficial mass, a bowel issue, or an enlarged internal organ. Seek emergency care immediately if a lump is accompanied by:
- Sudden, severe pain.
- A high fever.
- Vomiting.
- An inability to pass gas or stool.
- A distinctly pulsatile mass.