Bilateral ankle swelling

Think of ↑ pressure within the veins or lymphatic vessels or low albumin in the vascular space, bilateral damage to veins, lymphatics or capillaries due to local inflammation.

Some differential diagnoses and typical outline evidence

Right ventricular failure due to pulmonary hypertension or congestive cardiac failure	Suggested by: ↑JVP, liver enlargement and pulsation, RV heave. Onset over months usually.
	Confirmed by: dilated RV on echocardiogram.
	Management: OHCM pp136–9.
Poor venous return due to abdominal or pelvic masses, post-phlebitic or thrombotic venous damage	Suggested by: onset over months. Worse on prolonged standing or sitting, varicosities, venous eczema, pigmentation or ulceration. Non-pitting oedema if chronic.
	Confirmed by: clinically with Trendelenberg test showing filling along extent of communicating valve leaks or on venous Doppler ultrasound.
Low albumin states caused by liver failure, nephrotic syndrome, malnutrition, etc.	Suggested by: generalised oedema often including face after lying down. Onset usually over months.
	Confirmed by: low serum albumin.
	OHCD p694.
Bilateral cellulitis often associated with diabetes mellitus	Suggested by: warm, red and tender legs, thrombophlebitis and tracking, ulcers etc. Onset over days.
	Confirmed by: positive blood cultures (usually streptococcal or staphylococcal). (Blood sugar ↑ in diabetes.)
	Management: OHCM pp298, 456, 486, 548.
Inferior vena cava obstruction due to prolonged immobility, carcinoma, and oral combined contraceptive use)	Suggested by: bilateral leg swelling onset over hours, assoc. risk factors (obesity, smoker, FH). Symptoms of PE.
	Confirmed by: CT abdomen, low flow on Doppler ultrasound scan or filling defect on venogram.
	Management: OHCM p194.
Bilateral thromboses	Suggested by: onset over hours, risk factor of obesity, history of immobility, carcinoma, contraceptive. Assoc. PE. Leg(s) firm, warm, tender.
	Confirmed by: no flow on Doppler ultrasound scan or filling defect on venogram.
	Management: OHCM pp446, 456, 457.
Impaired lymphatic drainage	Suggested by: firm non-tender, non-pitting oedema of gradual onset over months to years.
	Confirmed by: obstruction to flow lymphangiogram.