The abdominal region, being the one with the most organs in our body, is more prone to pain from a multitude of different causes and diseases. Abdominal pain, popularly called tummy ache, is often a challenge for the physician, given the multitude of possible differential diagnoses.
Most of the time, abdominal pain is a benign and self-limiting event. Everyone has experienced mild abdominal pain that goes away without the need for medical treatment. However, when the abdominal pain is of strong intensity or there are other associated symptoms, such as fever, vomiting, prostration, or bloody diarrhea, a doctor’s evaluation is necessary.
In this article we will address the main causes of abdominal pain, explaining in a simple way how to distinguish between them. Don’t try to use this text to diagnose yourself, because without blood tests and imaging, diagnosing abdominal pain can be difficult even for doctors.
Abdominal and Pelvic Organs
In the illustrations below, we show the two ways of anatomically dividing the abdomen. This division serves to facilitate the description and interpretation of the physical examination. Use these illustrations to follow the explanations below about the main causes of abdominal pain.
All organs that are located within the abdominal cavity and pelvic cavity are possible sources of abdominal pain. Sometimes organs in the thoracic cavity can also cause abdominal pain, such as the heart or inflammation at the lung bases.
The organs inside the abdomen that can cause abdominal pain are: liver, gallbladder, bile ducts, pancreas, spleen, stomach, kidneys, adrenal glands, small intestine (duodenum, jejunum, and ileum), and colon (including appendix).
In the pelvic region, in turn, the organs that can be the source of abdominal pain are: ovaries, fallopian tubes, uterus, bladder, prostate, rectum, and sigmoid (final portion of the large intestine).
Location of abdominal pain
Because of the type of innervation of most abdominal organs, the brain has more difficulty locating the exact point of pain.
Most abdominal or pelvic organ problems cause pain that is diffuse or around the center of the abdomen. The exceptions are problems with the kidneys, gallbladder, ovaries, or appendix, where the pain is usually more lateral. In the illustration below you can see how the main abdominal and pelvic organs end up with pain located in regions that are very close to each other.
Therefore, the location of the pain is helpful, but usually not sufficient for a secure diagnostic hypothesis. In addition to the location, it is also important to evaluate other characteristics of the pain, such as: type (burning, cramping, shooting, pressure, etc.), duration, intensity, associated symptoms (such as vomiting, diarrhea, fever, or jaundice), aggravating or triggering factors, region to which the pain radiates, etc.
Most of the time, abdominal pain does not indicate any serious illness. Most cases are intestinal cramps associated with fatty foods or food poisoning. Mild abdominal pain that lasts for a short time or a few hours is usually due to gas-induced swelling of the intestines. Anxiety can also cause short-term abdominal pain by increasing the gas content in the intestines.
Worrying abdominal pain is pain that lasts for several hours, sometimes days, that is severe, disabling, or associated with vomiting, fever, and/or prostration.
Common causes of right-sided belly pain – right abdomen
Right-sided belly pain can be divided into right upper quadrant pain and right lower quadrant pain.
The main causes of pain in the upper right quadrant of the abdomen are found in the liver and gallbladder, most notably biliary colic, caused by gallstones or cholecystitis. Inflammations of the liver, as in cases of viral hepatitis, can also cause pain in this region.
In turn, lesions in the lower portion of the right lung can be responsible for right-sided abdominal pain that does not originate in the abdomen.
Regarding pain in the right lower quadrant of the abdomen, intestinal disorders are the most prevalent reasons, especially appendicitis. In women, ovarian problems, such as the presence of an ovarian cyst, are also very common causes (read: OVARY CISTS). An ectopic pregnancy in the right tube is another possible cause.
Eventually, problems in the testicle or a kidney stone that has migrated to the lower ureter can manifest with pain in the lower quadrant of the abdomen (left or right).
Pain of muscle origin should be considered if the patient has recently overexerted himself.
Common causes of pain in the middle of the belly – mouth of the stomach
Pain in the middle of the stomach, also called pain in the mouth of the stomach, is usually caused by stomach problems. Gastritis or peptic ulcer disease are the most common causes. Problems in the pancreas, such as pancreatitis, usually cause severe abdominal pain in the upper half of the abdomen, which can radiate to the back. Both stomach problems and pancreatic problems can cause a pain described as pain in the lower belly.
Muscle pain can also occur in this area.
The pain from an acute myocardial infarction can, in some cases, radiate to the middle of the abdomen, and you may initially mistake it for a stomach problem.
Common causes of lower abdominal pain
Abdominal pain in the lower abdomen, also called the lower abdomen or hypogastric region, usually originates in the bladder or uterus; the latter, of course, only in women.
Urinary infection (cystitis) and menstrual cramps are the most common causes.
Diarrheal conditions, such as viral gastroenteritis or food poisoning, can also cause pain in this region, but usually these are more dispersed throughout the abdomen.
Pregnancy doesn’t usually cause pain, just a feeling of heaviness. However, in the case of an ongoing abortion, there may be intense cramping.
Common causes of pain on the left side of the belly – left abdomen
As with the right side, belly pain on the left side can be divided into upper quadrant and lower quadrant pain.
In the upper left quadrant, the most common pains are those of muscle or stomach origin. Rarely, the spleen, an organ located below the ribs on the left side of the abdomen, is a cause of belly pain.
Like epigastric pain, a heart attack can also cause pain in the upper left quadrant of the belly.
Problems at the base of the left lung are other possible causes.
In the central and lower region of the left abdomen, on the other hand, intestinal problems, especially gastroenteritis and diverticulitis, are usually the main causes.
In women with pain in the lower left quadrant, ovarian dysfunction and a possible ectopic pregnancy should always be considered.
40 causes of abdominal pain
We will briefly discuss the 40 main diseases that cause abdominal pain. Use the links provided throughout the text to learn more details about each of the causes.
Gastritis and peptic ulcer
Gastritis and stomach ulcers or duodenum ulcers usually have similar symptoms: a burning pain in the upper abdomen, mainly in the epigastrium.
This pain in the stomach is called dyspepsia and usually appears when the stomach is empty. Its intensity is very variable and cannot be used to distinguish an ulcer from a simple gastritis.
The presence of blood in the stool or vomit associated with dyspepsia usually indicates a bleeding ulcer. Elderly people with dyspepsia and anemia without apparent cause should also be investigated for ulcers.
Cholecystitis and gall stones
The simple presence of gallstones , called cholelithiasis, does not usually cause symptoms. However, abdominal pain occurs if there is obstruction of the gallbladder drainage duct by one of these stones. If the obstruction is prolonged, there is cholecystitis, an inflammation of the gallbladder.
Called biliary colic, this pain is usually located in the right hypochondrium and epigastrium and appears soon after eating fatty foods. The pain of biliary colic may radiate to the back and right shoulder.
Simple biliary colic, without cholecystitis, usually appears more intensely in the first two hours after the last meal. When the pain is accompanied by fever and vomiting and does not improve over the hours, it is usually an indication of the presence of cholecystitis.
Inflammation of the pancreas, called acute pancreatitis , usually occurs in people who abuse alcohol.
This inflammation usually appears 1 to 3 days after heavy alcohol intake, manifesting as intense pain throughout the upper abdomen, including both the hypochondria and the epigastrium. In addition to lasting several days, this pain is often accompanied by vomiting and worsens after eating.
The term hepatitis refers to inflammation of the liver. The most common hepatitis are caused by viruses A, B or C. Acute hepatitis , however, can arise for several other reasons, such as drug intoxication or excessive alcohol consumption
Acute hepatitis usually causes ill-defined pain in the right hypochondrium and is associated with the presence of jaundice .
The kidney stone usually presents with intense pain in the lower back, unilaterally. It often radiates to the abdomen, particularly in the flanks. If the stone is obstructing the ureter near the bladder, the pain may be in the hypogastrium or iliac fossa, expanding into the scrotal region.
Renal colic is considered to be one of the most intense forms of pain a patient can experience.
The pain of appendicitis usually grows and starts diffusely, mainly around the umbilicus, and only goes to the lower right quadrant of the abdomen when it becomes more intense.
It is very common for the patient to also have fever, vomiting, and a well-hardened abdomen. Diarrhea is not common in appendicitis.
A diverticulum is a small pouch that forms in the wall of the large intestine (colon), similar to a glove finger, usually in people over 60 years of age. Its inflammation is called diverticulitis .
Most diverticula that inflame are located in the descending portion of the colon, located to the left of the abdomen. In 70% of cases, diverticulitis presents with pain in the lower left quadrant of the abdomen in people over 60 years of age. This pain lasts for several days and is usually accompanied by fever.
When inflammation of a diverticulum occurs in the ascending part of the large intestine (right), the symptoms are very similar to appendicitis.
Intestinal infection and diarrhea
Intestinal infections, whether bacterial or viral , are common causes of abdominal pain. The most common manifestation is abdominal cramping associated with diarrhea and/or vomiting.
Severe bacterial infections can lead to bloody diarrhea, a condition known as dysentery.
The intestinal parasites are also common cause of abdominal pain that can come with or without diarrhea.
Menstrual colic (dysmenorrhea)
The menstrual cramps occur in the lower abdomen, usually in the middle line, but may radiate to the back and thighs
Symptoms such as nausea, sweating, headache, loose stools and dizziness may be associated
Both cystitis (bladder infection) and pyelonephritis (kidney infection) can cause abdominal pain. Cystitis usually causes pain in the lower front associated with pain to urinate and frequent urination. Pyelonephritis, on the other hand, causes a more diffuse pain, including in the back, associated with intense malaise, fever, nausea, and vomiting.
Other 30 causes of abdominal pain
In addition to the causes described above, several others can also cause abdominal or pelvic pain, including:
- Tumors of the abdominal or pelvic organs.
- Intestinal obstruction
- Intestinal perforation
- Gastric perforation
- Infarction and intestinal ischemia.
- Splenic infarction
- Abdominal aortic aneurysm.
- Diabetic ketoacidosis
- Crohn’s disease or ulcerative rectocolitis
- Ovarian diseases
- Ectopic pregnancy
- Uterine myoma
- Liver abscess
- Splenic abscess
- Sickle cell anemia
- Polycystic kidneys
- Celiac disease
- Lactose intolerance
- Eosinophilic gastroenteritis
- Ovarian cyst
- Intussusception of the small intestine.
- Abdominal migraine.
- Acute intermittent porphyria
- Pelvic inflammatory disease
- Somatization (pain of psychological origin)
Causes of abdominal pain originating outside the abdomen
Some diseases of organs not located in the abdomen/pelvis can present abdominal pain. These types of manifestations are atypical, but are seen again and again in medical practice. Among these causes we can mention:
- Myocardial infarction.
- Hiatus hernia.
- Pleural effusion.
What is peritonitis?
The organs of the abdominal cavity are not loose inside the belly. They are surrounded by a highly vascularized and innervated membrane called the peritoneum.
Peritonitis, the inflammation of the peritoneum, is a serious condition, because it means that some abdominal infection/inflammation has become extensive enough to affect the peritoneum. Since it is highly innervated, the peritoneum is usually very painful when inflamed, and since it is highly vascularized, it facilitates the spread of bacteria from the abdominal region to the rest of the body, which can lead to sepsis.
The symptoms of peritonitis are intense diffuse abdominal pain, associated with a stiffening of the belly due to involuntary contraction of the abdominal muscles. The patient usually looks like a sick person. In addition, there is usually fever and associated vomiting.
A characteristic feature of peritonitis is intense pain when the stomach is squeezed and then quickly released. Unlike the other causes of abdominal pain, in which the pain is greatest during hand pressure, in peritonitis there is more pain when you take your hand away quickly than when you are squeezing your belly.
A characteristic of peritonitis is that there is intense pain when squeezing and then quickly releasing the belly. Unlike other causes, in which there is more pain when you press on your abdomen with your hands, in peritonitis there is more pain when you take your hand away quickly than when you are squeezing your belly.
Peritonitis is a common complication of several diseases, such as appendicitis, diverticulitis, perforations of the intestine or stomach, cholecystitis, etc., and should be treated with surgery to remove the inflamed/infected organ.
The presence of an abdominal inflammation with peritonitis is called an acute abdomen.
How to diagnose abdominal pain
In most cases, the investigation of a suspected abdominal pain is started with an ultrasound of the abdomen and pelvis. Most of the causes described above can be identified with this simple examination. In more difficult cases, a CT scan of the abdomen and pelvis is very helpful.
When injury is suspected inside hollow organs, such as the stomach and large intestine, digestive endoscopy and colonoscopy are, respectively, the best options for investigation.
- Abdominal Pain Mimics – Emergency Medicine Clinics of North America.
- The relationship between abdominal pain regions and specific diseases: an epidemiologic approach to clinical practice – Journal of epidemiology.