Right-side stomach pain can have many different causes, ranging from something as minor as constipation or trapped intestinal gas to more severe causes such as appendicitis and ectopic pregnancy. Any pain that occurs to the right of the imaginary line down the center of the midsection, through the belly button and down to the top of the genitalia is considered right-side stomach pain. Although many causes of this pain are usually not life-threatening, anyone who has severe or ongoing pain should be evaluated by a medical professional.

The right side of the abdominal cavity is home to many organs and bodily structures, and each one is a possible root of the pain. Organs include the appendix, liver, gallbladder, right kidney and part of the intestines. In women, the right ovary and fallopian tubes are also present. Structures include the blood vessels, the ureters that drain from the kidneys and the skin covering the entire region on the outside.

In many cases, right-side stomach pain is caused by relatively harmless conditions or factors. Trapped air in the intestines can cause abdominal discomfort, as can indigestion. Pain from a pulled muscle on the right side can radiate throughout the abdomen. Even a bruise or cut on the surface of the skin can cause pain in the underlying tissue that can be mistaken for deeper stomach pain.

In women, ovulation in the right ovary can cause right-side abdominal pain. In more severe cases, the pain might be caused by an ovarian cyst, ruptured ovary or ectopic pregnancy — a pregnancy that occurs inside the fallopian tube. When ovulation is the culprit, the pain is usually felt as a sharp twinge that fades within a day or so. Women who are experiencing extreme pain or a stabbing sensation should seek medical attention.

Appendicitis is one of the more severe causes of right-side stomach pain. The pain is usually felt in the lower right abdomen, below the level of the belly button, and it usually persists over several days, increasing in intensity. Additional signs of appendicitis include loss of appetite, chills, nausea and fever. The intensity of the pain typically increases during movement. People who suspect appendicitis should seek emergency medical attention, because a ruptured appendix can be fatal.

In some cases, the right-side stomach pain does not even originate in the stomach. Lung conditions can cause the pain to radiate downward from the site of the infection or disease, reaching the abdomen. A tumor in another part of the body can cause pain to travel down to the stomach region as well.