Unilateral Swelling of the Leg and Ankle

CLINICAL DIAGNOSTIC MANUAL

Unilateral swelling of the leg and ankle is a common condition that can result from various underlying causes, including vascular, lymphatic, infectious, and other pathologies. This swelling may indicate fluid accumulation in the soft tissues due to obstruction of blood or lymphatic flow. Identifying the underlying cause is crucial for appropriate treatment and to prevent potentially serious complications.

Pathology	Suspected Diagnosis	Confirmatory Diagnosis
Deep vein thrombosis (DVT)	Unilateral swelling, deep pain, skin colour changes, warmth sensation.	Doppler ultrasound, CT, blood tests for D-dimer.
Ruptured Baker’s cyst	Swelling and pain in the back of the knee and calf, history of popliteal cyst.	Ultrasound, MRI.
Cellulitis	Unilateral swelling, redness, warmth, pain, fever.	Physical examination, skin and tissue cultures.
Chronic venous insufficiency	Chronic swelling, varicose veins, skin changes, ulcers.	Doppler ultrasound, physical examination.
Venous insufficiency secondary to tumour or lymph node obstruction	Persistent unilateral swelling, palpable masses, skin colour changes.	CT, MRI, venography.
Immobility	Unilateral swelling in bedridden or limited mobility patients.	Clinical history, physical examination.
Lymphatic drainage disorder	Chronic swelling, thickened skin, changes in skin texture.	Lymphangiography, ultrasound.
Congenital oedema	Swelling present since birth or childhood, without other inflammatory symptoms.	Clinical history, ultrasound, genetic testing.
Acute lymphatic obstruction	Sudden swelling, pain, skin changes, history of surgery or infection.	Lymphangiography, CT, MRI.