Vomiting due to simple infection or food poisoning is usually self-limiting. Persistent vomiting, on the other hand, requires medical attention for assessment and to prevent dehydration. The sensation of hunger is physiological and can be generally accepted to signify a normal functioning digestive system.
Poor appetite may be due to any illness which affects the digestive function. If the problem is transient in nature, normal appetite will return quickly. Persistent appetite loss, especially with significant weight loss, will need early attention. This need not be associated with vomiting although the presence of additional vomiting will make a stronger case for immediate attention.
