Overview
Appendicitis is inflammation of the appendix, a small finger-shaped pouch attached to the large intestine on the lower right side of the abdomen. It typically comes on suddenly and worsens rapidly. Without treatment the appendix can burst, causing a serious, potentially life-threatening infection of the abdomen.
How common is it?
Appendicitis affects about 1 in 13 people at some point in their life. It is most common in people aged 10 to 30 but can occur at any age.
Causes and risk factors
The appendix becomes blocked, usually by hardened stool, mucus, or sometimes a small piece of food. Bacteria multiply rapidly inside the blocked appendix, causing swelling, increased pressure, and eventually infection.
Common risk factors
- Blockage of the appendix opening by hardened stool
- Enlarged lymph nodes in the abdomen from infection
- Intestinal parasites (in some regions)
- Age 10-30 years
- Male sex (slightly higher risk)
- Family history of appendicitis
Symptoms
- Sudden pain that starts around the navel and shifts to the lower right abdomen
- Pain that worsens over hours and with movement
- Nausea and vomiting
- Loss of appetite
- Low-grade fever
- Inability to pass wind
- Diarrhoea or constipation
When to see a doctor
Go to A&E immediately if you have severe abdominal pain that is worsening, especially if accompanied by fever and vomiting. Do not eat, drink, or take pain relief until assessed, as this may mask symptoms.
Diagnosis
Diagnosis is based on clinical examination, blood tests showing raised white cell count, urine tests to exclude kidney infection, and imaging. Ultrasound is used first, especially in children; CT scanning provides more detail in adults.
Treatments
Appendicectomy (appendix removal)
Standard treatment. Usually performed by keyhole surgery (laparoscopy) under general anaesthetic. Recovery takes 2 to 4 weeks for most people.
Antibiotics alone
In mild, uncomplicated cases without signs of perforation, antibiotics may resolve the episode, though many people eventually need surgery within 5 years.
Drainage of abscess
If the appendix has already perforated and formed an abscess, the infection is drained first, then surgery is performed several weeks later once inflammation has settled.
Self-care and lifestyle
- Full recovery from keyhole surgery usually takes 2 to 4 weeks
- Avoid heavy lifting and strenuous activity until cleared by your surgeon
- High-fibre diet after recovery may reduce risk of recurrence (evidence limited)
- Return to emergency immediately if fever, worsening pain, or wound redness develop after discharge
Prevention
There is no reliable way to prevent appendicitis, although a high-fibre diet is thought to reduce the risk of the blockages that trigger it.