A person with a poor appetite or no appetite may eat much less than normal or may not eat at all. A poor appetite can be caused by a changed sense of taste or smell, feeling full, tumor growth, dehydration, or the side effects of treatment.
A person may gag, cough, spit, feel pain, or have other problems when trying to swallow. There can be a number of causes. It may be a short-term side effect of chemo or radiation treatment to the throat or chest. It may also be caused by an infection of the mouth or esophagus, as well as other problems.
Cancer and its treatments can change your senses of taste and smell. These changes can affect your appetite and are often described as a bitter or metallic taste. Food can also taste too salty or sweet.