In short
Abdominal wall pain is often confused with pain from organs inside the abdomen, leading many patients through months of unnecessary tests and procedures before getting the right diagnosis and treatment.
What is abdominal wall pain?
Abdominal wall pain is pain that comes from the wall of your abdomen itself, rather than from the organs inside your belly. The abdominal wall includes the muscles, skin, nerves, and tissues that form the outer shell of your abdomen.
This condition is much more common than most people realize. Studies show that between 5% and 67% of patients who are sent to specialists for ongoing stomach pain actually have abdominal wall pain, not a problem with their internal organs. Unfortunately, many of these patients are initially told they have other conditions like irritable bowel syndrome, functional abdominal pain, or even psychiatric disorders.
One of the main problems with abdominal wall pain is that it often goes unrecognized for a long time. Research shows that the typical patient suffers for about 25 months before getting the correct diagnosis. During that time, they may undergo expensive laboratory tests, imaging scans, and even unnecessary procedures like endoscopy or gallbladder removal surgery, with annual healthcare costs exceeding $1,100.
Common causes
There are several reasons why pain can develop in the abdominal wall. The most common causes include nerve entrapment (when a nerve gets trapped or compressed), hernia, and complications from surgery or medical procedures.
Anterior cutaneous nerve entrapment syndrome is the most frequent type of abdominal wall pain and also the one that doctors miss most often. This happens when nerves that run through the abdominal wall become trapped or irritated. It can occur after abdominal surgery, where nerves get disrupted by surgical cuts, or sometimes as a result of hormonal changes.
Other conditions that can cause abdominal wall pain include problems with the abdominal aorta, increased pressure inside the abdomen, endometriosis, hernias, nerve problems that radiate from the spine, muscle pain, and complications from procedures like laparoscopy.
How it feels
Abdominal wall pain usually presents as sharp or chronic pain in a very specific, small area. The pain typically occurs at the lateral edge of the rectus abdominis (the vertical muscle that runs down the front of your abdomen) and gets worse when you change position or tense your abdominal muscles.
Patients can usually point to exactly where their pain is most intense, using just one or two fingers to show the spot. In about 40% of cases, the pain occurs in the right upper part of the abdomen, or it may be located in an area where there is a surgical scar.
The pain may get worse with certain activities, such as lying on the side where the pain is located. Unlike pain from internal organs, this pain stays in one spot and doesn't spread or move around.
How doctors identify it
Diagnosing abdominal wall pain requires a careful medical history and a targeted physical examination. Doctors should suspect abdominal wall pain when patients have no symptoms or signs pointing to a problem with internal organs, and when they can identify a small, tender spot on their abdomen.
A key test is called the Carnett test. During this test, the doctor presses on the tender spot while the patient tenses their abdominal muscles (usually by lifting their head and shoulders off the examination table). If the pain stays the same or gets worse when the muscles are tensed, this suggests abdominal wall pain rather than internal organ pain. With internal organ pain, tensing the muscles would typically make the pain feel better because the tight muscles act as a protective layer.
Doctors can confirm the diagnosis by injecting a local anesthetic into the painful area. If the pain improves by at least 50% after the injection, this confirms that the pain is coming from the abdominal wall. Point-of-care ultrasound may also help rule out other problems in the abdominal wall and guide the placement of injections.
Patients with abdominal wall pain often undergo extensive testing with laboratory studies, imaging scans, and endoscopic evaluations before the correct diagnosis is made, because doctors cannot figure out what is causing their pain.
Treatment options
The treatment for abdominal wall pain depends on what is causing it. Reassurance and patient education can be very helpful, as many patients are relieved to finally understand what is causing their pain.
For anterior cutaneous nerve entrapment syndrome, the most effective treatment is an injection of local anesthetic combined with a corticosteroid (a medication that reduces inflammation) directly into the painful area. This treatment has a very high success rate, with 70% to 99% of patients experiencing significant pain relief.
Some patients may need more than one injection for lasting relief. For those who continue to have pain after two or more injections, surgery to remove the affected nerve (neurectomy) generally resolves the pain completely.
Understanding the abdominal wall
The abdominal wall is made up of several layers of muscles that protect your internal organs. The main muscles include the rectus abdominis, transversus abdominis, external oblique, and internal oblique muscles.
The nerves in the abdominal wall control the function of these core muscles and provide sensation to the skin of the abdomen and groin area. When these nerves become trapped, irritated, or damaged, they can cause significant pain even though the organs inside the abdomen are perfectly healthy.
