A doctor told me when a patient's foot become swelled,it is very dangerous for his life .Is it right?

Dear Xman
That all depends on the reason for the swelling. The foot and the lower can swell due to a number of reasons, for example, a diet high in sodium, infection, venous insufficiency, lymphatic disorder, diabetes, trauma, baker's cyst, soft tissue mass, tumor, cardiac , pulmonary or renal disorder, medication etc...etc...It is impertavie to see your doctor for an thorough evaluation in order to determine the reason for the swelling, once a physical exam is performed and combined with other ancillary tests, you will be closer to establishing a more accurate diagnosis.

Good-luck and thank-you for contacting foot.com,
SBarlizo, DPM, CPed
foot.com expert