A Lump Along Your C-Section Scar: What It Might Be

By Your Health Magazine Health Information Team

You may notice it while showering, changing clothes, exercising, or pressing near your lower abdomen: a small lump along your C-section scar that was not obvious before. It may feel firm, soft, tender, or painless. Perhaps it changes size when you stand, cough, or have your period.

A lump near a cesarean incision is not automatically an emergency, and some changes are part of normal healing. However, several conditions can cause a lump in this area, including collected fluid, thickened scar tissue, infection, an incisional hernia, a reaction to surgical stitches, or scar endometriosis. The timing and behavior of the lump often provide important clues, but an examination is the only reliable way to determine the cause.

First, Consider When the Lump Appeared

If your C-section was recent, mild swelling and a firm ridge under the incision may be related to healing. Although the skin closes relatively quickly, deeper layers of tissue continue repairing themselves for months. The area may initially feel thicker, tighter, numb, itchy, or more sensitive than the surrounding skin.

A new lump that appears days or weeks after delivery may also be a fluid collection or wound complication. A lump that develops months or years later raises different possibilities, such as an incisional hernia, scar endometriosis, or a delayed reaction to suture material.

Possible Causes of a Lump Along a C-Section Scar

Normal Healing or Raised Scar Tissue

New scars commonly look and feel raised before gradually flattening. Some people form a hypertrophic scar, which is a thickened scar that follows the incision line. Others develop a keloid, an overgrowth of scar tissue that can extend beyond the original incision.

Raised scars may feel firm, itchy, sensitive, or tight, particularly when clothing rubs against them. Unlike a hernia, thick scar tissue generally does not disappear when you lie down or become noticeably larger when you cough.

Seroma or Hematoma

A seroma is a pocket of clear fluid that can collect beneath the skin after surgery. It may feel soft, squishy, or fluid-filled and can create a pulling sensation around the incision. Small seromas may be absorbed by the body, while larger, painful, or persistent collections may require evaluation and drainage by a healthcare professional.

A hematoma is a collection of blood within the tissues. It is more likely to appear soon after surgery and may be associated with bruising, firmness, tenderness, or swelling. Because fluid collections can interfere with healing or become infected, contact your maternity or surgical care team if swelling is increasing rather than improving.

Wound Infection or Abscess

An infected incision may become increasingly painful, swollen, warm, or red. On darker skin tones, redness may be less noticeable, so warmth, worsening tenderness, skin discoloration, drainage, and changes in how you feel can be especially important. Pus, an unpleasant odor, fever, chills, or the wound beginning to open also require prompt attention.

An abscess is a localized collection of pus and may feel like a painful lump under or beside the scar. It should not be squeezed, punctured, or drained at home. Medical treatment may involve antibiotics, professional drainage, wound care, or a combination of these measures.

Incisional Hernia

A C-section requires an opening through several layers of the abdominal wall. If a weakened area remains after healing, fat or part of the intestine may push through it, creating an incisional hernia.

A hernia-related lump often becomes more prominent when you stand, cough, strain, exercise, lift something, or have a bowel movement. It may flatten or disappear when you lie down. Some hernias are painless, while others cause aching, pressure, or discomfort that becomes more noticeable during an active day.

A clinician can often identify a hernia during a physical examination. Ultrasound or other imaging may be used when the diagnosis is unclear or when more information is needed before treatment planning.

Scar Endometriosis

Endometriosis occurs when tissue similar to the lining of the uterus grows outside the uterus. In uncommon cases, endometriosis develops within the abdominal wall near a previous cesarean incision.

A classic sign is a firm, painful lump that becomes more tender or swollen before or during menstruation. Some people experience burning, pulling, or localized pain, while others have discomfort that is not clearly linked to their cycle. Symptoms can appear long after the C-section, which may make the connection easy to miss.

Tell your healthcare professional if the lump changes with your menstrual cycle. Ultrasound is frequently used to evaluate the area, and MRI may sometimes provide additional information. A tissue examination is generally needed to confirm the diagnosis. Learn more about endometriosis and its often-overlooked symptoms.

Suture Granuloma

A suture granuloma is an inflammatory reaction around surgical stitch material. It may produce a small, firm nodule within or close to the scar, sometimes months or years after surgery. The area may be painless, tender, irritated, or associated with persistent drainage.

Because a suture reaction can resemble an infection, endometriosis, or another type of mass, imaging and occasionally removal of the tissue may be needed to establish the cause.

How the Cause Is Identified

Your healthcare professional will ask when you first noticed the lump and whether it is changing. Helpful details include whether it:

Appeared soon after surgery or developed much later
Hurts, itches, burns, drains, or feels warm
Changes with coughing, lifting, standing, or lying down
Becomes more painful or swollen around menstruation
Has grown, hardened, or changed color
Is accompanied by fever, nausea, constipation, or abdominal pain

The examination may be performed while you are lying down and standing. You may be asked to cough or tighten your abdominal muscles so the clinician can check for a hernia. Ultrasound can distinguish some solid masses from fluid collections and may reveal an abdominal-wall defect. CT or MRI may be appropriate in selected cases. If the diagnosis remains uncertain, a tissue sample or surgical removal may be recommended.

What You Can Do While Waiting for Evaluation

Avoid repeatedly pressing, squeezing, or trying to puncture the lump. If your incision is still healing, follow your maternity team’s wound-care instructions and keep the area clean and dry. Note any changes in size, pain, drainage, or skin color. If you menstruate, tracking symptoms across one or two cycles may help your clinician recognize a pattern.

Do not assume that every lump is scar tissue or attempt to force a painful bulge back into place. Treatment depends on the cause and may range from observation to medication, drainage, hernia repair, or removal of abnormal tissue. For broader information about pregnancy and postpartum health, visit the MedlinePlus pregnancy health resource.

When to Seek Care

Arrange an appointment with an obstetrician-gynecologist, primary care clinician, or the surgical team that performed your C-section if a new lump persists, grows, becomes painful, drains, or changes with your menstrual cycle. A general surgeon may be involved if an incisional hernia or abdominal-wall mass is suspected.

Seek same-day medical advice for increasing redness, warmth, swelling, pain, foul-smelling drainage, pus, fever, feeling unwell, or separation of the incision. Go to an emergency department for sudden severe pain, vomiting, abdominal bloating, inability to pass stool or gas, or a bulge that becomes hard, very tender, discolored, or remains stuck in place. These symptoms may indicate an obstructed or strangulated hernia or another complication requiring urgent treatment.

Most causes of a lump along a C-section scar can be evaluated with a focused history, examination, and appropriate imaging. Paying attention to when the lump appeared and what makes it change can help your healthcare professional reach the correct diagnosis more efficiently.