Severe upper abdominal pain can be due to a wide variety of medical conditions, some of which are serious. Here’s list of the top five causes of severe upper abdominal pain.
1. Gallstones
Gallstones are a very common cause of upper abdominal pain. The gall bladder is a small pouch which sits near the liver. The purpose of the gall bladder is to concentrate bile before it enters the small intestine. Bile is an important player in our digestive process and allows us to break down fats. 
Gallstones can form for a variety of reasons. Being overweight, pregnant or older can increase your risk of gallstones.
Gallstones cause upper abdominal pain when they become stuck in either the gallbladder, or the tube which takes bile from the gallbladder to the small intestine (the bile duct). The term ‘biliary colic’ refers to the waves of pain which occur when the gallbladder contracts to try and force bile against the gallstone.
Complications such as infection and inflammation can occur.
2. Infections / Gastroenteritis
Gastroenteritis is an infection in the gastrointestinal tract (the digestive system / gut). Viruses such as norovirus are the most common cause of gastroenteritis. Symptoms include vomitting, diarrhoea, crampy abdominal pain and dehydration.
Hand washing is one of the best ways to prevent gastroenteritis, viruses are easily transmitted from person to person so important
3. Ulcers
Stomach ulcers are another common cause of upper abdominal pain. Ulcers fall under the category of ‘Peptic Ulcer Disease’ (PUD). Stomach ulcers commonly form due to infection by a bacteria known as Helicobacter Pylori. The bacteria disrupts the stomach wall which results in stomach acid forming an ulcer.
Treatment is often a course of antibiotics. It is important to treat ulcers as they can cause bleeding into the stomach.
4. Heart problems
Although not common, it is possible for heart problems such as heart attacks (myocardial infarctions) and angina to cause pain in the upper abdominal region.
5. Lung problems
Lung infections in the base (bottom) of the lungs may also sometimes cause pain in the upper abdominal region.
