Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem. Most frequently the cause is benign and/or self-limited, but more serious causes may require urgent intervention.

Introduction

Abdominal pain is traditionally described by its chronicity (acute or chronic), its progression over time, its nature (sharp, dull, colicky), its distribution (by various methods, such as abdominal quadrant (left upper quadrant, left lower quadrant, right upper quadrant, right lower quadrant) or other methods that divide the abdomen into nine sections), and by characterization of the factors that make it worse, or alleviate it.

Due to the many organ systems in the abdomen, abdominal pain is a concern of general practitioners/family physicians, surgeons, internists, emergency medicine doctors, pediatricians, gastroenterologists, urologists and gynecologists. Occasionally, patients with rare causes can see a number of specialists before being diagnosed adequately (e.g., chronic functional abdominal pain)

Types and mechanisms

1. The pain associated with the abdomen of inflammation of the parietal peritoneum (the part of the peritoneum lining the abdominal wall) is steady and aching, and worsened by changes in the tension of peritoneum caused by pressure or positional change. It is often accompanied by tension of the abdominal muscles contracting to relieve such tension.
2. The pain associated with obstruction of a hollow viscus (as opposed to peritoneal and solid organ pain) is often intermittent or "colicky", coinciding with the peristaltic waves of the organ. Such cramps are exactly what is experienced with early acute appendicitis and gastroenteritis and are somewhat relieved by writhing and massage.
3. The pain associated with abdominal vascular disturbances (thrombosis or embolism) can be sudden or gradual in onset, and can be severe or mild. Pain associated with the rupture of an abdominal aortic aneurysm may radiate to the back, flank, or genitals.
4. Pain that is felt in the abdomen may be "referred" from elsewhere (e.g., a disease process in the chest may cause pain in the abdomen), and abdominal processes can cause radiated pain elsewhere (e.g., gall bladder pain—in cholecystitis or cholelithiasis—is often referred to the shoulder).

Causes

The following is an incomplete list of possible causes of abdominal pain.Cartwright SL, Knudson MP. Evaluation of Acute Abdominal Pain in Adults. Am Fam Physician. 2008;77(7):971-978.

• Gastrointestinal
• Inflammatory: gastroenteritis, appendicitis, gastritis, esophagitis, diverticulitis, Crohn's disease, ulcerative colitis, microscopic colitis
• Obstruction: hernia, intussusception, volvulus, post-surgical adhesions, tumours, superior mesenteric artery syndrome, severe constipation
• Vascular: embolism, thrombosis, hemorrhage, sickle cell disease, abdominal angina, blood vessel compression (such as celiac artery compression syndrome)
• digestive: peptic ulcer, lactose intolerance, celiac sprue, Jasohnstritis
• Bile system
• Inflammatory: cholecystitis, cholangitis
• Obstruction: cholelithiasis, tumours
• Liver
• Inflammatory: hepatitis, liver abscess
• Pancreatic
• Inflammatory: pancreatitis
• Renal and urological
• Inflammation: pyelonephritis, bladder infection
• Obstruction: kidney stones, urolithiasis, Urinary retention, tumours
• Vascular: left renal vein entrapment
• Gynecological or obstetric
• Inflammatory: pelvic inflammatory disease
• Mechanical: ovarian torsion
• Endocrinological: menstruation, Mittelschmerz
• Tumors: endometriosis, fibroids, ovarian cyst, ovarian cancer
• Pregnancy: ruptured ectopic pregnancy, threatened abortion
• Abdominal wall
• muscle strain or trauma
• muscular infection
• neurogenic pain: herpes zoster, radiculitis in Lyme disease, abdominal cutaneous nerve entrapment syndrome (ACNES), tabes dorsalis
• Referred pain
• from the thorax: pneumonia, pulmonary embolism, ischemic heart disease, pericarditis
• from the spine: radiculitis
• from the genitals: testicular torsion
• Metabolic disturbance
• uremia, diabetic ketoacidosis, porphyria, C1-esterase inhibitor deficiency, adrenal insufficiency,lead poisoning, black widow spider bite, narcotic withdrawal
• Blood vessels
• aortic dissection, abdominal aortic aneurysm
• Immune system
• sarcoidosis
• vasculitis
• familial Mediterranean fever
• Idiopathic
• irritable bowel syndrome (affecting up to 20% of the population, IBS is the most common cause of recurrent, intermittent abdominal pain)