what can be the cause of loss of taste
A gradual loss of smell and taste may be due to a cold/flu or sinus infection. If after the cold or sinus infection has cleared up, your sense of smell and taste has not returned, it is important that you visit your GP so that he/she can identify any underlying cause for your loss of smell or taste.
Taste - impaired. Taste impairment means there is a problem with your sense of taste. Problems range from distorted taste to a complete loss of the sense of taste. A complete inability to taste is rare. The tongue can detect sweet, salty, sour, savory and bitter tastes. Much of what is perceived as taste is actually smell. People who have taste problems often have a smell disorder that can make it hard to identify a food's flavor. (Flavor is a combination of taste and smell.) Taste problems can be caused by anything that interrupts the transfer of taste sensations to the brain. It can also be caused by conditions that affect the way the brain interprets these sensations.