A common background problem
The patient already had visible varicose veins and occasional ankle swelling, making the new complaint easy to dismiss.
The dangerous difference
This time the swelling was mainly one-sided and had developed after prolonged travel. The calf felt tense and uncomfortable.
The twist
Assessment confirmed deep-vein thrombosis. The old diagnosis had distracted from a new vascular event.
Take-home message
New unilateral leg swelling is different from chronic symmetric dependent oedema. Consider thrombosis when there are risk factors such as immobility, surgery, cancer, pregnancy or previous VTE.
Diagnostic principle: do not let the first plausible label stop the search when an important detail does not fit.
Educational note: This is a teaching composite, not a substitute for patient-specific diagnosis or treatment. Real patients require direct clinical assessment and appropriate investigations.