Appendicitis: Symptoms, Diagnosis, Treatment and Nursing Care

Appendicitis is inflammation of the vermiform appendix, most often following obstruction of its lumen. It is an important cause of acute abdominal pain and a surgical emergency because inflammation may progress to gangrene, perforation, peritonitis or an intra-abdominal abscess. Early recognition, prompt referral, careful observation and timely treatment reduce preventable complications.

These lecture notes explain the anatomy, causes, pathophysiology, clinical features, assessment, investigations, differential diagnosis, treatment options and nursing management of appendicitis. They are intended for nursing education; individual assessment and treatment decisions must be made by the responsible clinical team using current local protocols.

By the end of this lesson, the learner should be able to:

• Define appendicitis and describe the relevant anatomy of the appendix.
• Explain the usual pathophysiology and possible complications.
• Recognise typical and atypical symptoms and signs and describe a systematic abdominal assessment.
• Discuss investigations and the role and limitations of clinical risk scores.
• Differentiate appendicitis from other causes of acute abdominal pain.
• Outline medical, operative and selected non-operative management.
• Plan safe pre-operative and post-operative nursing care and provide appropriate health education.

Appendicitis is acute or chronic inflammation of the vermiform appendix. In everyday clinical practice, the term usually refers to acute inflammation. The appendix is a narrow, blind-ended tube attached to the caecum near the ileocaecal junction.

• Uncomplicated appendicitis: inflammation without established gangrene, perforation, abscess or diffuse peritonitis. Definitions can vary between studies and local protocols.
• Complicated appendicitis: appendicitis with perforation, gangrene, abscess, phlegmon or peritonitis. An appendicolith may increase the risk of complications or failure of antibiotic-first treatment, but should be interpreted with the full clinical picture.
• Appendicular mass or phlegmon: an inflammatory mass formed when the omentum and adjacent bowel wall off the inflamed or perforated appendix.
• Appendicular abscess: a localised collection of pus related to perforated appendicitis.
• Appendicectomy / appendectomy: surgical removal of the appendix.

The vermiform appendix is a blind-ended, muscular tube arising from the posteromedial wall of the caecum, usually a short distance below the ileocaecal valve. Its base can be located by following the convergence of the three taeniae coli on the caecum. Its length and position vary between individuals.

• Retrocaecal or retrocolic: behind the caecum or ascending colon; pain and tenderness may be less obvious in the anterior right lower quadrant, and psoas irritation may occur.
• Pelvic: descends into the pelvis; may cause suprapubic discomfort, urinary frequency, diarrhoea or rectal discomfort, and obturator irritation.
• Subcaecal: lies below the caecum.
• Pre-ileal or post-ileal: lies in front of or behind the terminal ileum.
• High or ectopic positions: uncommon positions can alter the site of pain; a long appendix may extend to another abdominal region.

The appendicular artery, usually a branch of the ileocolic artery, runs in the mesoappendix and behaves as an end artery. Progressive swelling can compromise venous and then arterial flow, predisposing the appendix to ischaemia and gangrene. The appendix contains gut-associated lymphoid tissue and may contribute to mucosal immunity; it is not essential for normal digestion.

Acute appendicitis commonly begins when the narrow appendicular lumen becomes obstructed. Obstruction may be related to lymphoid hyperplasia after infection, a faecolith or appendicolith, parasites, a foreign body or, less commonly, a tumour. In some cases no clear obstructing cause is identified.

• Age: appendicitis is common in children, adolescents and young adults, but it can occur at any age.
• Lymphoid tissue enlargement following gastrointestinal or other infection.
• Faecolith or appendicolith obstructing the lumen.
• Parasitic infestation in some settings.
• Rarely, an appendiceal or caecal neoplasm, particularly in older adults or after an abscess.
• Family history may be associated with increased risk, although this does not determine whether an individual will develop appendicitis.

1. Luminal obstruction: secretions and mucus continue to accumulate behind the obstruction.
2. Distension: the appendix stretches, increasing intraluminal pressure and stimulating visceral nerve fibres. This produces vague, poorly localised periumbilical or central abdominal pain.
3. Venous and lymphatic congestion: rising pressure impairs drainage; the appendiceal wall becomes oedematous and inflamed.
4. Bacterial multiplication and tissue injury: normally present intestinal organisms multiply in the obstructed lumen and inflammation extends through the wall.
5. Local parietal peritoneal irritation: when inflammation reaches the adjacent parietal peritoneum, pain becomes sharper and localises, often to the right lower quadrant.
6. Ischaemia and gangrene: worsening vascular compromise may cause tissue necrosis.
7. Perforation: a weakened area may rupture. Containment by omentum and bowel may create a local abscess or phlegmon; free leakage can cause generalised peritonitis and sepsis.

• Abdominal pain: often starts as vague periumbilical or epigastric discomfort and later moves to the right iliac fossa / right lower quadrant. It commonly worsens with coughing, walking, bumps in a vehicle or movement. Some patients have pain from the start in the right lower quadrant.
• Anorexia: loss of appetite is common.
• Nausea and vomiting: nausea or one or more episodes of vomiting may occur, often after the onset of pain. Repeated vomiting or vomiting before the pain should prompt consideration of other causes as well.
• Altered bowel habit: constipation can occur; some patients, especially with a pelvic appendix, have loose stool or diarrhoea.
• Low-grade fever: may appear as inflammation progresses. High fever, rigors or marked systemic illness raise concern for perforation, abscess or sepsis, but fever may be absent, especially early.
• Urinary symptoms: frequency, urgency or discomfort may occur if an inflamed pelvic appendix irritates the bladder or ureter. Urinary symptoms also require assessment for urinary tract disease.

• Patient may lie still and guard the abdomen; movement may increase pain.
• Local tenderness, commonly near McBurney's point in the right lower quadrant.
• Involuntary guarding or rebound tenderness may indicate peritoneal irritation. Repeatedly eliciting pain is unnecessary; assess gently and follow local practice.
• Reduced bowel sounds may occur with peritonitis or ileus; early bowel sounds can be normal.
• Pulse may be raised and temperature mildly elevated; assess the overall trend and hydration.
• A palpable right lower abdominal mass may suggest an appendicular mass or abscess, but examination alone cannot confirm it.

Clinical caution: these signs have limited sensitivity and should be assessed by trained clinicians only when appropriate. A negative sign does not rule out appendicitis, and vigorous or repeated manoeuvres can cause unnecessary pain.

• Young children: may not describe pain migration; symptoms can include irritability, poor feeding, vomiting, fever, diarrhoea or diffuse tenderness. Perforation risk is higher when diagnosis is delayed.
• Older adults: pain, fever and guarding may be less pronounced; comorbidities and other acute abdominal conditions make assessment more complex. Maintain a low threshold for escalation when the patient is deteriorating.
• Pregnancy: nausea and abdominal discomfort can overlap with normal pregnancy symptoms. As the uterus enlarges, the appendix may be displaced upward, so pain may not be at the classic point. Use urgent senior/surgical and obstetric review and appropriate pregnancy-safe imaging.
• Retrocaecal appendix: anterior right lower quadrant tenderness may be subtle; flank or back discomfort and psoas irritation can occur.
• Pelvic appendix: suprapubic discomfort, urinary frequency, diarrhoea or pelvic tenderness may predominate.
• Immunocompromised patients: inflammatory signs can be muted even when serious infection is present.

Assessment should be structured, respectful, timely and repeated when the diagnosis is uncertain or the patient changes. Acute abdominal pain can deteriorate quickly. Follow the facility's triage and escalation process while the clinician evaluates the likely cause.

• When did the pain start? Was onset sudden or gradual? Where was it first felt, where is it now, and has it moved?
• Ask the patient to describe the pain: character, severity, duration, radiation, pattern and aggravating or relieving factors.
• Ask about appetite, nausea, vomiting, fever, bowel movements, passage of flatus, urinary symptoms and previous similar episodes.
• Ask about last menstrual period, possibility of pregnancy, vaginal bleeding or discharge, and relevant gynaecological history where applicable.
• Ask about previous abdominal operations, known hernias, gastrointestinal or urinary disease, allergies, medications, recent antibiotics, chronic conditions and relevant family history.
• Clarify food and fluid intake, last oral intake, alcohol or substance use when clinically relevant, and the patient's baseline function.
• Use open, non-judgemental questions; obtain a collateral history when needed, especially for a child, confused patient or someone too unwell to provide details.

1. Primary survey: assess airway, breathing, circulation, disability and exposure as appropriate. Identify shock, sepsis, severe dehydration or rapidly worsening pain immediately.
2. Observations: measure and trend temperature, pulse, blood pressure, respiratory rate, oxygen saturation, pain score, mental status and urine output as indicated.
3. General inspection: observe posture, movement, pallor, sweating, dehydration and distress. Allow privacy and a chaperone when required.
4. Abdominal examination: inspect for distension, scars or hernias; auscultate as appropriate; gently palpate away from the painful area first, then assess local tenderness, guarding and any mass. Assess for signs of peritonitis using the least painful appropriate method.
5. Additional examination: a clinician may assess groins, rectum or pelvis when indicated by the differential diagnosis. Explain, obtain consent, use a chaperone and follow local policy.
6. Reassessment: document findings, time and changes. New generalised pain, increasing tenderness, fever, tachycardia, hypotension, confusion or reduced urine output requires urgent escalation.

No single investigation diagnoses every case. Results must be interpreted with the history, examination and clinical course. A normal early test does not always exclude evolving disease.

Scores such as the Alvarado, Appendicitis Inflammatory Response (AIR) and Adult Appendicitis Score (AAS) combine features like pain migration, tenderness, fever, white-cell count, neutrophils and inflammatory markers. Paediatric Appendicitis Score (PAS) may support assessment in children. Scores can help stratify risk and decide who needs observation or imaging; they are decision aids, not stand-alone diagnostic tests. Use the score recommended by the local team and do not allow a low score to override concerning clinical deterioration.

Right lower quadrant pain has many causes. A differential diagnosis is especially important in women of reproductive age, children, older adults and anyone with atypical symptoms.

The classic migration of pain to the right lower quadrant supports appendicitis, but the absence of migration does not exclude it. Urinary or gynaecological findings may point to another diagnosis, but they can also coexist with appendicitis or result from an adjacent inflamed appendix.

Appendicitis requires prompt clinical or surgical assessment. The choice between surgery, antibiotics-first care or treatment of a contained abscess depends on whether disease is uncomplicated or complicated, age, pregnancy, imaging, comorbidities, patient preferences, available surgical and radiology services, and the local protocol.

• Urgently refer a suspected case for clinical and surgical review; escalate immediately if there are signs of peritonitis, sepsis or shock.
• Assess ABCs, vital signs, pain, hydration, allergy history, current medicines, pregnancy possibility and relevant comorbidities.
• Keep the patient nil by mouth when surgery or urgent intervention is possible, following the clinician's instructions and facility policy.
• Establish intravenous access when indicated; collect ordered tests and administer prescribed fluids, analgesia, antiemetics and antibiotics.
• Analgesia should be given as prescribed and response reassessed; appropriate pain relief does not replace serial examination.
• Administer pre-operative antimicrobial prophylaxis or therapeutic antibiotics at the prescribed time. Selection and duration should follow current local guidance, allergies, severity and antimicrobial policy.
• Do not give laxatives or enemas for suspected appendicitis. Avoid applying heat to the abdomen. Neither should delay urgent evaluation.
• Prepare for imaging, transfer or theatre; explain care, preserve dignity, document findings and communicate changes promptly.

Appendectomy is the standard definitive treatment for many patients and laparoscopic appendectomy is the usual preferred approach when expertise and equipment are available. Open surgery may be selected when laparoscopy is unavailable, unsuitable or needs conversion for safety. The surgeon removes the appendix, controls contamination, inspects the abdomen and sends the specimen for histopathology according to local practice.

• Uncomplicated disease: appendectomy is commonly performed during the admission. Current WSES guidance states that selected uncomplicated cases may be scheduled within 24 hours of admission without increased adverse outcomes; this does not apply to a deteriorating patient who needs urgent intervention.
• Peri-operative antibiotics: prophylaxis is given before incision as prescribed. Routine prolonged post-operative antibiotics are generally not needed after adequate source control for uncomplicated disease; the surgical team determines the regimen.
• Complicated disease: surgery may be needed for perforation or peritonitis. After adequate source control, current WSES guidance supports a short post-operative antibiotic course in many patients rather than prolonged treatment; duration depends on response and local policy.
• Drains: a drain is not placed routinely after every appendectomy; the decision is individualised by the operating team.

Antibiotics without immediate appendectomy may be discussed for carefully selected patients with imaging-confirmed uncomplicated appendicitis who are clinically stable, have no diffuse peritonitis or abscess, can be monitored and can return promptly if symptoms worsen. Shared decision-making should cover the possibility of treatment failure, recurrence and later appendectomy. An appendicolith may increase the likelihood of failure or complications and should be considered in selection.

This pathway is not appropriate for every patient and is not a reason to delay surgical review. Patients need a clear follow-up plan and explicit return precautions. The decision should be made by the treating clinical team with the patient, taking into account local capacity and preferences.

A contained abscess or phlegmon is managed individually. Options may include intravenous antibiotics, image-guided drainage when a drainable collection and expertise are available, or surgery. Urgent surgery may be needed when the patient is unstable, has generalised peritonitis or fails non-operative treatment. After non-operative treatment of an appendiceal abscess, planned clinical follow-up is important. The 2025 WSES guideline highlights the need to consider an underlying appendiceal neoplasm, particularly in older adults; decisions about interval surgery and/or surveillance should be made by the surgical team according to age, imaging, patient factors and local guidance.

• Relieve obstruction/inflammation and control the source of infection.
• Prevent perforation, peritonitis, abscess and sepsis.
• Correct dehydration and electrolyte disturbance.
• Provide safe pain and nausea control.
• Support early recovery, nutrition and return to activity.
• Identify patients who need follow-up after non-operative treatment or complications.

The nurse contributes through early recognition, careful observation, preparation, symptom relief, prevention of avoidable harm, psychological support, clear documentation and patient education. Nursing care must follow the prescribed plan and local policy; suspected appendicitis needs timely clinical review.

1. Airway and breathing: receive the patient with a structured handover; assess airway patency, respiratory effort, oxygen saturation and level of consciousness. Position and give oxygen as prescribed.
2. Circulation and observations: monitor pulse, blood pressure, temperature, respiratory rate, oxygen saturation and pain according to recovery-room and ward policy. Report trends suggesting bleeding, sepsis or deterioration.
3. Pain and nausea: assess pain and nausea regularly, administer prescribed medicines and evaluate effectiveness. Escalate severe or increasing pain rather than assuming it is routine post-operative pain.
4. Wound and drains: inspect dressings and port sites for bleeding, discharge, redness or separation. If a drain is present, observe amount, colour and patency and document output.
5. Fluids and elimination: maintain prescribed IV fluids, monitor intake/output, assess hydration and encourage urination when safe. Report oliguria, persistent vomiting or abdominal distension.
6. Gastrointestinal recovery: assess bowel sounds and return of oral tolerance as directed; advance diet according to the surgeon's plan and local practice. Encourage fluids and suitable food once permitted.
7. Mobility and breathing exercises: assist early mobilisation and encourage deep breathing/coughing as appropriate, supporting the wound if needed. Follow activity restrictions and fall-prevention measures.
8. Infection prevention: perform hand hygiene, use aseptic technique for wound care, give antibiotics only as prescribed and monitor for fever, increasing tenderness, wound infection or intra-abdominal abscess.
9. Psychological care: explain expected recovery, listen to concerns and provide culturally respectful support.
10. Documentation and handover: record observations, interventions, response, wound/drain status, intake/output, escalation and patient teaching. Give a clear handover to the next nurse or care setting.

• Perforation: rupture of the appendiceal wall.
• Local abscess or appendicular mass: contained infection around the appendix.
• Generalised peritonitis: widespread inflammation following leakage into the peritoneal cavity.
• Sepsis and septic shock: systemic response to infection that can cause organ dysfunction and circulatory collapse.
• Paralytic ileus: temporary reduction in bowel motility due to inflammation, infection or surgery.
• Adhesions and bowel obstruction: can occur after intra-abdominal inflammation or surgery.
• Pylephlebitis / portal venous infection: rare but serious septic thrombophlebitis.

• Wound infection, bleeding, haematoma or wound separation.
• Intra-abdominal collection or abscess, particularly after perforation.
• Persistent ileus, nausea, vomiting or delayed oral tolerance.
• Injury to adjacent bowel or other structures, uncommon but important.
• Venous thromboembolism, especially in higher-risk or immobile patients.
• Adverse effects of anaesthesia, analgesia or antimicrobial medicines.

• Explain the diagnosis and treatment plan using language the patient understands; clarify whether the appendix was removed or treated without surgery.
• Take prescribed medicines exactly as instructed. Do not use leftover antibiotics or stop a prescribed course without advice.
• Keep the wound clean and follow the discharge instructions for dressing, bathing and follow-up.
• Resume food, fluids, walking, school/work and lifting gradually according to the surgical team's advice.
• Attend review appointments, especially after antibiotic-first treatment, appendicular abscess or complicated appendicitis.
• Seek urgent care for worsening abdominal pain, fever, repeated vomiting, fainting, wound discharge, increasing redness, abdominal swelling or inability to pass urine or stool.
• For non-operative treatment, recurrence or worsening can occur; the patient should know exactly where and how to return for review.

• Appendicitis is a common surgical cause of acute abdominal pain; obstruction and inflammation can progress to ischaemia, gangrene and perforation.
• Classic pain begins centrally and migrates to the right lower quadrant, but atypical patterns are common.
• Anorexia, nausea and vomiting support the history; their absence does not exclude appendicitis.
• McBurney's point, Rovsing, psoas and obturator signs can support assessment but are not definitive tests.
• Always consider ectopic pregnancy and ovarian torsion in patients who could be pregnant; consider urinary, gastrointestinal and other surgical causes.
• Use clinical scores and imaging as aids. A score or normal blood test alone must not override clinical deterioration.
• Urgent surgical review is essential. Laparoscopic appendectomy is the standard operative approach when feasible; selected stable patients with uncomplicated disease may discuss antibiotics-first care.
• Perforation, abscess, phlegmon, peritonitis and sepsis classify the more complicated presentations and change management.
• Nursing priorities include serial observations, nil by mouth when ordered, prescribed IV fluids/medicines, preparation for investigation or theatre, safe post-operative monitoring and clear return precautions.
• Do not give laxatives or enemas or apply abdominal heat to suspected appendicitis.

1. Define appendicitis and describe the common positions of the appendix.
2. Explain how luminal obstruction can lead to migration of pain and then perforation.
3. List six common symptoms or signs of acute appendicitis.
4. Describe three atypical presentations and explain why diagnosis may be delayed in those groups.
5. What is the difference between an appendicular mass, phlegmon and abscess?
6. List investigations used when appendicitis is suspected and state one limitation of each.
7. Name four important differential diagnoses in a woman of reproductive age with right lower abdominal pain.
8. Outline pre-operative and post-operative nursing care for a patient undergoing appendectomy.
9. Identify five signs that may indicate perforation, peritonitis or sepsis.
10. What health education should be given to a patient treated with antibiotics without immediate appendectomy?

• Ministry of Health, Republic of Uganda. Uganda Clinical Guidelines, 2023. Consult the current Ministry of Health guidance and local facility protocol.
• Podda M, Ceresoli M, De Simone B, et al. Diagnosis and Treatment of Acute Appendicitis: 2025 Edition of the World Society of Emergency Surgery Jerusalem Guidelines. JAMA Surgery. 2026;161(3):283–295. doi:10.1001/jamasurg.2025.6218.
• Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). Guideline for the Diagnosis and Treatment of Appendicitis. 2024.
• Hernandez MC, et al. SAGES guideline for the diagnosis and treatment of appendicitis. Surgical Endoscopy. 2024;38:2974–2994.

Last updated: October 2026. These notes support learning and do not replace clinical assessment, a qualified prescriber's decision or current local guidance.