Rebound tenderness, also called Blumberg’s sign, is something your doctor might check for when diagnosing peritonitis.

Peritonitis is the inflammation of the membrane on the inside of your abdominal wall (the peritoneum). It’s usually caused by an infection, which can be the result of many things.

Read on to learn more about how a doctor checks for rebound tenderness and what it means for your health.

To check for rebound tenderness, a doctor applies pressure to an area of your abdomen using their hands. They quickly remove their hands and ask if you feel any pain when the skin and tissue that was pushed down moves back into place.

If you do feel pain or discomfort, you have rebound tenderness. If you don’t feel anything, it helps your doctor to rule out peritonitis as a cause of your symptoms.

If you experience rebound tenderness, you might also have some of the following symptoms:

  • stomach pain or tenderness, especially when you move
  • feelings of fullness or bloating, even if you haven’t eaten anything
  • fatigue
  • unusual thirst
  • constipation
  • reduced urination
  • loss of appetite
  • nausea
  • vomiting
  • fever

Make sure to tell you doctor about any of these symptoms, including when you first noticed them and anything that makes them better or worse.

Rebound tenderness is a sign of peritonitis, a serious condition that is an inflammation of the peritoneum. This inflammation often results from an infection.

Many things can cause the underlying infection, including:

  • Perforation. A hole or opening in your abdominal wall can let bacteria in, either from your digestive tract or from outside your body. This can cause an infection of your peritoneum that can lead to an abscess, which is a collection of pus.
  • Pelvic inflammatory disease. Pelvic inflammatory disease (PID) results from an infection of the female reproductive organs, including the uterus, fallopian tubes, or ovaries. Bacteria from these organs can move into the peritoneum and cause peritonitis.
  • Dialysis. You may need catheter tubes inserted into your kidneys through your peritoneum to drain fluid during dialysis. An infection can happen if the tubes or medical facility aren’t properly sterilized.
  • Liver disease. Scarring of liver tissue, known as cirrhosis, can cause ascites, which refers to the buildup of fluid in your abdomen. If too much fluid builds up, it can cause a condition called spontaneous bacterial peritonitis.
  • Surgery complication. Any kind of surgery, including in your abdominal area, carries a risk of infection in the surgical wound.
  • Ruptured appendix. An infected or injured appendix can burst, spreading bacteria into your abdomen. An abdominal infection can quickly turn into peritonitis if your ruptured appendix isn’t removed or treated right away.
  • Stomach ulcer. A stomach ulcer is a sore that can appear on your stomach lining. A certain type of ulcer known as a perforated peptic ulcer can create an opening in the stomach lining, causing an infection in the abdominal cavity.
  • Pancreatitis. Inflammation or infection of your pancreas can spread into your abdominal cavity and cause peritonitis. Pancreatitis can also cause a fluid called chyle to leak from your lymph nodes into your abdomen. This is known as acute chylous ascites and can cause peritonitis.
  • Diverticulitis. Diverticulitis happens when small pouches in your intestines, called diverticula, get inflamed and infected. This can cause perforations in your digestive tract and make you vulnerable to peritonitis.
  • Abdominal injury. Trauma or injury to your abdomen can injure your abdominal wall, making the peritoneum more susceptible to inflammation, infection, or other complications.

If you think you have peritonitis, see your doctor right away.

An abdominal infection can lead to serious complications if it’s left untreated.

If a doctor finds that you do have rebound tenderness, they’ll likely follow up with a few other tests to narrow down a diagnosis.

These tests include:

  • Guarding vs. rigidity test. Guarding involves voluntarily flexing your abdominal muscles, making your abdomen feel firm to the tough. Rigidity is abdominal firmness that’s not related to flexing muscles. Your doctor can tell the difference by gently touching your abdomen and seeing if firmness decreases when you relax.
  • Percussion tenderness test. A doctor will gently but firmly tap on your abdomen to check for pain, discomfort, or tenderness. The abrupt tapping will likely cause pain if you have peritonitis.
  • Cough test. You’ll be asked to cough while a doctor checks for any flinching or other signs of pain. If coughing causes pain, you may have peritonitis.

Depending on your other symptoms, a doctor might order some laboratory tests as well, including:

They may also use a CT scan or MRI scan to look at your abdominal tissue and organs.

If a doctor confirms that you have peritonitis, there are several treatment options, depending on the underlying cause. These include:

  • antibiotics for bacterial infections
  • surgery to remove infected tissue, a burst appendix, diseased liver tissue, or to address issues in your stomach or intestines
  • pain medication for any pain or discomfort from inflammation

Rebound tenderness isn’t a condition itself. Instead, it’s usually a sign of peritonitis. Without quick treatment, peritonitis can cause lasting health complications.

Seek immediate medical attention if you experience unusual abdominal bloating and pain, especially if you haven’t eaten anything recently.