Abdominal pain is pain that you feel in the abdominal area (the area between your chest and groin), often referred to as the stomach region or belly. Even when you feel pain there, however, it may originate from somewhere else -- like your chest, pelvic region (the area just below the abdomen that houses the reproductive organs), or a generalized infection affecting many parts of your body (like the flu or strep throat).

There are many organs in the abdomen. Pain in the abdomen can originate from any one of them, including:

• Organs related to digestion -- the stomach, the end of the esophagus, the small and large intestines, the liver, the gallbladder, and the pancreas.
• The aorta -- a large blood vessel that runs straight down the inside of the abdomen.
• The appendix -- an organ in the right lower quadrant that no longer serves much function.
• The kidneys -- two bean shaped organs that lie deep within the abdominal cavity.

The intensity of the pain does not always reflect the seriousness of the condition causing the pain. Severe abdominal pain can be from mild conditions, such as gas or the cramping of viral gastroenteritis (a virus that causes inflammation along the lining of the stomach and intestines). On the other hand, relatively mild pain (or no pain) may be present with life-threatening conditions, such as cancer of the colon or early appendicitis .

The severity of the condition has more to do with the suddenness of the pain, especially if it is sharp and localized to one region, rather than spread throughout your abdomen.

Many different conditions can cause abdominal pain, as illustrated in the list below. The key is to know when you must seek medical care right away. In many cases you can simply wait, use home care remedies, and call your doctor at a later time only if the symptoms persist.

Possible causes include:

• Excessive gas
• Chronic constipation
• Lactose intolerance (milk intolerance)
• Viral gastroenteritis (stomach flu)
• Irritable bowel syndrome (sensitive stomach with intermittent episodes of diarrhea and constipation)
• Heartburn or indigestion
• Gastroesophageal reflux
• Ulcers
• Cholecystitis (inflammation of the gallbladder) with or without gallstones
• Appendicitis (inflammation of the appendix)
• Diverticular disease, including inflammation of small pouches that form in the large intestines (diverticulitis)
• Bowel obstruction -- in addition to pain, this causes nausea, bloating, vomiting, and inability to pass gas or stool
• Food allergy
• Food poisoning (salmonella, shigella)
• Hernia
• Kidney stones
• Urinary tract infections
• Pancreatitis (inflammation of the pancreas)
• Intussusception (telescoping intestines) -- while uncommon, this is a serious possible cause of pain in an infant who may be drawing his or knees to the chest and crying to indicate the pain
• Dissecting abdominal aortic aneurysm -- bleeding into the wall of the aorta
• Parasite infections (Giardia)
• Sickle cell crisis
• Crohn's disease or ulcerative colitis (two different types of inflammatory bowel disease)

When an inflammed organ in the abdomen ruptures or leaks fluid, you not only have excruciating pain, your abdmon will be very stiff (board-like) and you will likely have a fever. This occurs when you have peritonitis due to an infection spreading in the abdominal cavity from the ruptured organ, like the appendix. This is a medical emergency.

In infants, prolonged unexplained crying (often called "colic") may be caused by abdominal pain that often ends with the passage of gas or stool. Colic is often worse in the evening. Cuddling and rocking the child may bring some relief.

Abdominal pain that occurs during menstruation may be from menstrual cramps or it may indicate a problem in a reproductive organ. This includes conditions such as endometriosis (when tissue from the uterus is displaced to somewhere else like the pelvic wall or ovaries), uterine fibroids (thick bands of muscular and fibrous tissue in the uterus), ovarian cysts, ovarian cancer (rare), or pelvic inflammatory disease (PID) -- infection of the reproductive organs, usually from a sexually transmitted disease.

Abdominal pain may actually be caused by an organ in the chest, like the lungs (for example, pneumonia) or the heart (like a heart attack). Or, it may stem from a muscle strain in the abdominal muscles.

Cancer of the colon, stomach, or pancreas are serious but uncommon causes of abdominal pain.

Other more unusual causes of abdominal pain include a type of emotional upset called somatization disorder, reflected as physical discomfort (including recurrent abdominal pain). Strep throat in children can cause abdominal pain.