Can't taste salt - what's up with that?

Don't get me wrong, I am not a big "salter". But three days ago, I suddenly stopped tasting the salt in foods. Everything I eat now tastes extremely bland with no flavor. These are foods that I know what to expect and the taste just isn't there. A slice ofo tomato or avocado for example. Or some deli turkey. It is like eating cardboard.

Does anyone have any idea what would cause this?

Thank you.

Dianna