DEAR MAYO CLINIC: What causes an inguinal hernia? Will I need surgery to repair it even if it's not painful? If so, what does the surgery involve?

ANSWER: Although the cause isn't always apparent, an inguinal hernia occurs when a weakened area in your lower abdominal muscles gives way enough so that soft tissue protrudes through the muscle wall into the groin area. While the opening by itself isn't dangerous, it may pose a threat -- possibly even life-threatening -- if soft tissues get trapped in that opening. That's why it's important to have your doctor check a noticeable or painful bulge that occurs in your groin on either side of your pubic bone.

Identifying an inguinal hernia is the first step in deciding if surgical repair is an option, and if so, how soon it should be done. An inguinal hernia is just one type of hernia that commonly develops in the abdominal area, and the most common type requiring surgical treatment.

Development of an inguinal hernia is usually related to increased pressure in the abdomen: like straining during bowel movements or urination, chronic coughing or sneezing, lifting heavy objects, or even with pregnancy or fluid in the abdomen.

Some inguinal hernias don't cause any symptoms and may go unnoticed until discovered during a routine medical exam. If you stand up -- and especially if you cough or strain -- symptom-free hernias can often be seen and felt as a bulge in the area on either side of your pubic bone. The bulge of an inguinal hernia usually contains the soft, fatty tissue called omentum; more advanced hernias may contain part of your intestine or bladder. Other signs and symptoms may include a burning, gurgling or aching sensation in your groin; sharp pain or discomfort in your groin, especially when bending over, coughing or lifting; and a sensation of weakness or pressure in your groin.

Inguinal hernias that move in and out of the opening -- depending on whether you're lying down or standing -- often can be gently massaged back into the abdomen by your doctor.

A more serious concern arises if the omentum or intestine becomes trapped in the abdominal wall and can't be massaged back inside. The hernia is then termed "incarcerated." It is stuck, which is not risky by itself, but it is a progression toward potential trouble. The risk is that it may become strangulated, meaning the blood supply to the bowel is cut off. This can lead to gangrene of the bowel and is potentially fatal.

Signs and symptoms of a strangulated hernia may include nausea, vomiting or both, pain that intensifies quickly, fever, rapid heart rate, a hernia bulge that's tender and skin that's red, purple or dark. If you experience any of these, call your doctor right away or seek immediate medical attention. Emergency surgical treatment is necessary to restore blood supply to the intestine and repair the hernia.

The definitive inguinal hernia treatment is surgery. These repairs are among the most commonly performed surgical procedures. Your doctor may suggest observation if your hernia isn't bothering you. Many studies suggest that surgery shouldn't be done before symptoms arise. However, as soon as even mild symptoms arise, your doctor may want you to consider surgery.

The two general types of hernia repair operations are the traditional open and the minimally invasive laparoscopic. During open repair, a surgeon makes an incision in the groin and pushes the protruding omentum or intestine back into the abdomen and closes the opening. Synthetic mesh is often used to reinforce the weak area. Laparoscopic repair is performed through several small abdominal incisions.

Generally, an overnight hospital stay is not required with these procedures. After open repair, it may take three to four weeks before you're fully able to resume all of your normal activities. Laparoscopic surgery may allow for a quicker return to regular activities.

Laparoscopic repair isn't suited for everyone. Very large inguinal hernias are better managed with open repair, including those where the intestine is pushed down into the scrotum. Scarring from previous abdominal or pelvic surgery -- such as surgery to remove your prostate gland (prostatectomy) -- makes laparoscopic inguinal hernia repair difficult to do. Your overall health and any medical conditions you may have are important factors in determining what type of surgery might be best for you. -- David Farley, M.D., General Surgery, Mayo Clinic, Rochester, Minn.

(Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care. E-mail a question to medicaledge@mayo.edu. For more information, visit http://www.mayoclinic.org.)

(c) 2014 MAYO FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH. DISTRIBUTED BY TRIBUNE CONTENT AGENCY, LLC. ALL RIGHTS RESERVED.