What is appendicitis?
Appendicitis is inflammation (swelling) and infection of your appendix. The appendix is a small finger-shaped organ attached to your large intestine.
The appendix is an organ that doesn’t have a necessary function. You don't need your appendix to live a healthy life.
Appendicitis is most common in teens and young adults and rare before the age of 1
Symptoms include belly pain (usually in the lower right belly), low fever (100 to 101° F [37.7° to 38.3° C]), and throwing up
It can be hard for doctors to tell if your child has appendicitis or another problem—they'll do blood tests and ultrasound
Appendicitis is a medical emergency and your child will need surgery
What causes appendicitis?
Appendicitis sometimes happens when the appendix is blocked either by:
Hard stool (poop)
Lymph nodes (tiny, bean-shaped organs that help fight off infections) in the intestine that swell because of an infection
Regardless of what's blocking it, the appendix swells and bacteria grow. If it isn't treated, the appendix can break open cause infection inside your belly (called peritonitis).
What are the symptoms of appendicitis?
Symptoms include:
Pain in the middle of the belly that moves to the lower right side
In babies and children, pain may happen all over the belly
Throwing up and not wanting to eat
Low fever of 100 to 101° F (37.7° to 38.3° C)
How can doctors tell if my child has appendicitis?
It can be hard to be sure your child has appendicitis. If doctors think your child has appendicitis, they'll do:
Blood tests
Ultrasound
If the ultrasound Ultrasonography Ultrasonography is a safe imaging test that uses sound waves to create a moving picture of the insides of your body. Ultrasonography doesn't use radiation (x-rays). Ultrasonography is also called... read more 
result isn't clear, doctors may:
Observe your child and repeat the physical exam, looking for signs that it's getting worse
Do a CT scan Computed Tomography A CT scan uses a large machine shaped like a large donut to take x-rays from many angles. A computer then takes the x-rays and creates many detailed pictures of the inside of your body. Each... read more
or MRI Magnetic Resonance Imaging (MRI) MRI is a test that uses a machine with a powerful magnet to make pictures of the inside of your body. A computer records changes in the magnetic field around your body. The computer then uses... read more 
How do doctors treat appendicitis?
Doctors treat appendicitis by doing surgery to remove the appendix (appendectomy). Untreated appendicitis can be deadly.
The best time to operate is before the appendix bursts. If the appendix has already burst, the doctor:
Removes the appendix
Washes out the insides of your child's belly with fluid
Gives antibiotics for several days
Watches for problems, such as infection or blocked intestines
