hi, On a temporary basis, many people find that their senses of taste ( gustatory ) and smell ( olfactory) are impaired by illness. A person with a cold or flu, even at its final stages, usually has enough congestion that the senses of both smell and taste are limited, if not almost nonexistent. In this instance, the lack of ability to taste serves to illustrate the strong link between gustation and olfaction:. The taste buds themselves are working fine, but the lack of smell, resulting from congestion, hinders the brain s ability to process flavor. Another cause of this horrible or icky taste in your mouth during a bout with the flu is ketosis. While sick with the flu, you might have loss of appetite. During starvation and in the absence of carbohydrates (CHO) or glucose, the liver will convert the fat reserves ( glycogen) into fatty acids and ketones for energy.. Influenza is a viral disease that usually strikes between October and May. It lasts from three to five days and can be followed by fatigue for two or three weeks. It usually causes aching muscles and joints, headaches, cough and fever with a temperature of between 38 and 40C.Because it is a viral infection, it cannot be treated with antibiotics. Antiviral agents can reduce the severity and duration of infection, but these are generally prescribed only if there are concerns regarding complications of the infection or transmission of more severe strains of the virus. The best remedy is rest while drinking plenty of fluids.THANK YOU.