Appendicitis in Adults: Causes, Diagnosis and Treatment

Appendicitis in adults is an inflammation of the appendix, usually triggered when its opening gets blocked and infected, and it is diagnosed using a combination of symptoms, abdominal examination, blood tests and imaging, then treated in most cases by removing the appendix, often through laparoscopic surgery. The typical pattern is pain that starts around the navel and shifts to the lower right abdomen, with nausea, poor appetite and fever. Because many other conditions cause similar pain, a proper medical evaluation on the same day is important.

In this article, we look at why appendicitis happens, how doctors separate it from other causes of abdominal pain, and what treatment and recovery involve for adults.

Why Does Appendicitis Happen?

The appendix is a narrow pouch that opens into the large intestine. When the opening becomes blocked, mucus and bacteria build up inside, pressure rises and blood supply to the wall reduces. This leads to inflammation, infection and, if untreated, a risk of the appendix bursting.

Common triggers

• A small hardened piece of stool (faecolith)
• Swelling of lymphoid tissue in the appendix wall, sometimes following a viral or bacterial infection
• Less commonly, parasites, foreign material or a growth

Who is at risk?

Appendicitis can occur at any age, although it is most common between the teenage years and the thirties. A family history may slightly increase risk. There is no reliable way to prevent it.

How Symptoms Usually Progress

Symptoms often develop over 12 to 48 hours:

1. Early stage: vague discomfort or cramping around the navel, loss of appetite
2. Next few hours: nausea or vomiting, pain moving to the lower right abdomen
3. Later: pain becomes sharper and constant, worse with movement or coughing, low-grade fever

Not everyone follows this pattern. In pregnancy, older age, diabetes or when the appendix lies in an unusual position, pain may be felt in the back, flank, pelvis or upper abdomen. Read more about right-side vs left-side stomach pain.

Other Conditions That Can Mimic Appendicitis

Part of the diagnosis is ruling out other causes of lower abdominal pain, such as:

• Gastroenteritis (stomach infection)
• Kidney stones or urinary tract infection
• Ovarian cysts, ovarian torsion, pelvic infection or ectopic pregnancy in women
• Inflammatory bowel disease
• Gallbladder problems, especially if the pain is higher up. See our article on gallstones and biliary pain
• Constipation and trapped gas
• Diverticulitis, more often in older adults

How Is Appendicitis Diagnosed in Adults?

Step 1: History and examination

The doctor asks how and where the pain started, how it changed and what makes it worse. On examination, they check for tenderness in the lower right abdomen, guarding (tightening of the muscles) and pain on releasing pressure.

Step 2: Laboratory tests

• Complete blood count to look for raised white blood cells
• C-reactive protein (CRP) as a marker of inflammation
• Urine test to look for infection or blood from a stone
• Pregnancy test in women of childbearing age

Step 3: Imaging

• Ultrasound: often the first scan, especially in younger and slimmer adults and in pregnancy
• CT scan: gives a clear picture in many adults and helps identify complications
• MRI: may be used in pregnancy when ultrasound is inconclusive

Step 4: Clinical decision

The surgeon combines all findings. Scoring systems that use symptoms, signs and blood results can help estimate the likelihood of appendicitis and guide the next step.

Treatment Pathways

Uncomplicated appendicitis

When the appendix is inflamed but has not burst, the usual treatment is appendectomy after starting antibiotics and fluids. In selected adults, antibiotics alone may be discussed, with the understanding that appendicitis can recur in some people.

Laparoscopic surgery

Keyhole surgery uses small incisions, a camera and fine instruments to remove the appendix. It also allows the surgeon to look at nearby organs. Many people experience less wound discomfort and a faster return to daily activities compared with open surgery. Learn more about laparoscopic appendectomy.

Complicated appendicitis

If the appendix has burst, formed an abscess or caused widespread infection, treatment may include a longer course of antibiotics, drainage of pus and surgery that may be done urgently or after the infection settles. Hospital stay is usually longer.

Open surgery

Sometimes an open operation is safer or necessary, depending on findings during surgery or the patient’s condition.

Recovery and Return to Routine

• Start walking soon after surgery, as advised
• Begin with fluids and light meals, then return to a balanced diet
• Take prescribed medicines and complete any antibiotic course
• Keep wounds clean and dry
• Avoid lifting heavy weights for the period advised by your surgeon
• Attend the follow-up visit

Contact your doctor if you develop fever, worsening pain, vomiting, redness or discharge from wounds, or difficulty passing stools or gas.

Frequently Asked Questions

Who is most likely to get appendicitis?

Appendicitis is most common in teenagers and young adults, but it can occur at any age. Older adults may have less typical symptoms, which can delay diagnosis.

How do doctors tell appendicitis from other stomach pain?

They look at how the pain started and moved, examine the abdomen for specific tenderness, and use blood tests and imaging. Other causes such as gastroenteritis, kidney stones, urinary infection, gynaecological conditions and gallbladder problems are considered and ruled out.

Is right-side abdominal pain always appendicitis?

No. Pain on the right side can come from the gallbladder, liver, kidney, ovary, bowel or muscles. Pain in the lower right abdomen with fever, nausea and loss of appetite raises concern for appendicitis and needs prompt evaluation.

Can I live normally without my appendix?

Yes. People live normally after the appendix is removed. It does not affect digestion in any noticeable way.

What should I eat after appendix surgery?

Most people start with fluids and light, easily digestible foods, then return to a normal balanced diet over a few days. Fibre and fluids help prevent constipation. Follow the specific advice given by your surgeon.

When can I return to work after appendix surgery?

After uncomplicated laparoscopic surgery, many people return to desk work in about one to two weeks. Physical jobs and heavy lifting usually need longer. Recovery is slower if the appendix had burst.

Consult Dr. Ujwal Zambare

If you have abdominal pain that is new, persistent or worsening, a timely evaluation can help identify the cause. Dr. Ujwal Zambare (MBBS, MS General Surgery, DNB Surgical Gastroenterology) is a consultant surgical gastroenterologist and laparoscopic surgeon in Wakad. Learn more about appendicitis treatment.

You can also request an appointment through the contact page.