A number of medical conditions can change your sense of smell which can then have an affect on your sense of taste.
Colds or sinus problems are probably the most coomon.
Meningiomas are brain tumors taht can also lead to a change of smeel suddenly. They commonly occur in mid-life and show a distinct female predilection. The best test for their diagnosis are a CT/ MRI of the head.
In your case I would advise that you get yourself examined by a physician who can then decide as to what tests may be appropriate,
For a more detailed list of possible causes read here
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regards
Dr. Gupta
Edited by GauravMD on January 15 2006 at 1:13 PM