Red flag symptoms: Abdominal pain

Identifying potentially serious causes of abdominal pain.

Red flag symptoms

  • Sudden onset abdominal pain
  • Haematemesis
  • Unexplained weight loss
  • Change in bowel habit for > 3 weeks
  • Unexplained PV bleeding
  • Post-coital bleeding
  • Shortness of breath
  • Dysphagia
  • Increased vaginal discharge
  • Bloodstained vaginal discharge
  • Pre-syncopal symptoms
  • Haematuria
  • Fever
  • New onset dyspepsia
  • Persistent unexplained vomiting
  • Amenorrhoea
  • Testicular pain

Abdominal pain is a common presenting problem in primary care. Many potentially life-threatening diagnoses present with acute abdominal pain.

However, a focused history and examination should lead to a diagnosis and appropriate management.


Begin by locating the pain and ask the patient how and when it began and what they were doing at the time. Ask about severity and whether the pain radiates elsewhere. Are they acutely unwell?

Are there any aggravating or relieving factors, and has the pain eased, remained constant or worsened? Is it colicky, relieved by defecation, or altered following ingestion of food?

Ask about GI symptoms, including changes in bowel habit, rectal bleeding, nausea, vomiting, haematemesis, heartburn, odynophagia or dysphagia.

If diarrhoea and vomiting predominate, has there been a history of foreign travel? Does the patient work with food? Is anyone else unwell in the family?

Enquire about weight and be alert to any weight loss.

Urological symptoms may be very relevant, particularly if a renal or lower urinary tract cause is suspected. Determine whether the patient has undergone any abdominal surgery.

In women, pay close attention to gynaecological symptoms and ascertain whether the patient could be pregnant. Cardiac pain can also present as epigastric pain, thus associated shortness of breath and vomiting may be relevant.

A sexual history may be relevant if PID is suspected. Has there been any recent change in sexual partners or any known exposure to chlamydia or gonorrhoea?

A careful drug history, including OTC drugs, may yield clues. The patient may be taking medications that could aggravate dyspepsia, such as bisphosphonates, NSAIDs or SSRIs. There may be a history of opiate use leading to constipation. 

Enquire about smoking and alcohol intake.

It is also very important to consider whether the patient has presented with similar pain before and if so, whether this was investigated, and the outcome of any investigations. Is there a history of recent endoscopy or abdominal imaging such as ultrasound or CT scanning?


Careful observation of how the patient enters the room will provide much information. Check BP, pulse, oxygen saturation and temperature.

Is the patient well hydrated? Is the patient jaundiced? Is there evidence of anaemia?  Is there any stigmata of chronic liver disease? Does the abdomen look distended? If so, is there evidence of ascites? Weigh the patient if there is a history of weight loss.

Palpate the abdomen systematically focusing on all nine areas. Is there any evidence of guarding, rigidity or percussion pain? Are there any noted masses or evidence of organomegaly? Rectal examination may be necessary.

Check hernial orifices if the history suggests that an inguinal hernia is a possible cause. It may be important to listen for bowel sounds. You may wish to check the testicles if testicular torsion is suspected.

Potentially life-threatening diagnoses

  • MI
  • Perforated viscus
  • Ruptured abdominal aortic aneurysm
  • Ectopic pregnancy
  • Acute pancreatitis
  • Acute cholecystitis
  • IBD
  • Renal stone
  • Bowel obstruction
  • Diabetic ketoacidosis
  • PID
  • Incarcerated inguinal hernia
  • Pyelonephritis
  • Ischaemic colitis
  • Acute hepatic failure
  • Appendicitis
  • Diverticulitis


Investigations will be guided by the history and any findings on examination, but could include the following:

  • bloods (including FBC, U&Es, CRP, Hba1c, amylase, LFTs and ESR)
  • Urinalysis looking for UTI or evidence of renal calculi
  • ECG
  • stool testing for Helicobacter pylori
  • stool culture and sensitivity (C/S)
  • faecal calprotectin
  • chest X-ray (right basal pneumonia can present with right upper quadrant pain)
  • urinary hCG
  • triple swabs
  • abdominal, pelvic or renal ultrasound.

Plain abdominal film can be considered if constipation is suspected, a HAD score if a psychological cause is suspected, and an AUDIT questionnaire if alcohol dependence is suspected.

Tumour markers are not recommended in the primary care setting although CA125 can be considered if ovarian malignancy is suspected.

Depending on local resources, CT abdomen and pelvis can be considered although most CT investigations are undertaken in secondary care.

Additional diagnoses

Additional diagnoses to consider in children include mesenteric adenitis, and abdominal migraine. Diabetic ketoacidosis can present with an acute abdomen.

  • Dr Singh is a GP in Northumberland

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This is an updated version of an article that was first published in October 2011

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