Abdominal Swelling
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Abdominal swelling requires a careful assessment to distinguish benign causes from serious pathology. It may be due to distension of any intra-abdominal organ, fluid, fat, flatus, or a mass.
History and Examination
Take a focused history addressing:
- Onset and duration (acute vs gradual)
- Associated symptoms: pain, change in bowel habits, weight loss, nausea, vomiting, urinary symptoms
- Gynaecological history in women: LMP, menstrual irregularities, pregnancy
- Alcohol intake and risk factors for liver disease
On examination:
- Assess for ascites, organomegaly, masses, and bowel sounds
- Look for signs of chronic liver disease
- Consider a pelvic exam if gynaecological pathology is suspected
Common Causes of Abdominal Swelling
| Cause | Distinguishing Features |
|---|---|
| Fat (Obesity) | Generalised, non-tender distension; slow onset; consistent with overall body habitus. |
| Flatus (Bloating) | Intermittent distension, often worse after meals; may be associated with IBS; relieved by passing wind. |
| Faeces (Constipation) | Palpable left-sided mass; history of infrequent stools or straining; may have discomfort or bloating. |
| Fluid (Ascites) | Fluctuant abdomen; shifting dullness; fluid thrill; may have signs of liver disease, malignancy or heart failure. |
| Foetus (Pregnancy) | Progressive central swelling; amenorrhoea; positive pregnancy test; fetal movements in later stages. |
| Ovarian cysts | Lower abdominal/pelvic swelling; may be asymptomatic or cause pressure symptoms; normal bowel habit. |
| Fibroids | Firm, irregular pelvic mass; menorrhagia or pressure symptoms; non-tender unless very large. |
| Bladder retention | Suprapubic distension; dull to percussion; difficulty passing urine; relief post-catheterisation. |
| Mass (e.g. tumour) | Localised, firm or hard mass; may be associated with weight loss, early satiety or systemic symptoms. |
| Hepatosplenomegaly | Upper quadrant fullness; may be tender; associated with liver disease, haematological or infectious causes. |
Red Flags
Refer urgently if:
- Unintentional weight loss
- Palpable mass
- Ascites without known liver disease
- Postmenopausal bleeding
- New-onset bloating in women >50 years (consider ovarian cancer)
Investigations
Initial tests in primary care:
- FBC, U&E, LFTs, CRP, CA125 (Ovarian cancer), CA19-9 ( Pancreatic cancer), CEA (Bowel cancer)
- Urinalysis
- Pregnancy test
- Abdominal and pelvic ultrasound
Consider faecal calprotectin or FIT depending on other symptoms.
Management
- Treat underlying cause if known
- Refer to secondary care for imaging or further assessment if:
- Persistent symptoms
- Diagnostic uncertainty
- Red flags