Appendicitis
This is an inflammation of the appendix,(a tube of tissue connected to the large intestine.) 
The symptoms include sharp pain in the lower right abdomen, the pain typically begins around your navel and then shifts to your lower right abdomen. Appendicitis pain increases over a period of 12 to 18 hours and gradually becomes very severe’.
Thefirst symptom is often pain around your belly button. (See: Abdominal pain) The pain may be minor at first, but it becomes more sharp and severe. Your appetite will be reduced, and you may have nausea, vomiting, and a low fever.
Symptoms of Appendicitis?
The classic symptoms of appendicitis include:
- Dull pain near the navel or the upper abdomen that becomes sharp as it moves to the lower right abdomen. This is usually the first sign.
- Loss of appetite
- Nausea and/or vomiting soon after abdominal pain begins
- Abdominal swelling
- Fever of 99-102 degrees Fahrenheit
- Inability to pass gas
Almost half the time, other symptoms of appendicitis appear, including:
- Dull or sharp pain anywhere in the upper or lower abdomen, back, or rectum
- Painful urination
- Vomiting that precedes the abdominal pain
- Severe cramps
- Constipation or diarrhea with gas
If you have any of these symptoms, go to the ER. An infected appendix must be surgically removed or it will eventually burst, spreading the infection within the abdomen. This can result in life-threatening complications. Read more about Appendicitis here
Sources: Medical Encyclopedia, Appendicitis WebMD, Appendicitis National Institute of Diabetes and Digestive and Kidney Mayo Clinic http://www.mayoclinic.com/health/appendicitis/DS00274, U.S. National Library of Medicine – The World’s Largest Medical Library