Old age; chronic disease; medications such as narcotics, chemotherapy drugs and antibiotics; pregnancy; and pancreatic, ovarian or colon cancer are some of the common reasons for loss of appetite, states Healthgrades. Some people also experience poor appetite due to alterations to their senses of smell or taste.
Poor appetite, which is medically known as anorexia, occurs in people with conditions related to the digestive system, and it also affects individuals suffering infections, dehydration or other generalized conditions, explains Healthgrades. It is rarely a symptom of a serious condition. During the first trimester of pregnancy, women may experience poor appetite and other symptoms, such as nausea or vomiting.
Chronic diseases associated with lack of appetite include kidney failure, hepatitis, chronic obstructive pulmonary disease and heart failure, according to Healthgrades. Older people are vulnerable to loss of appetite due to a reduction in daily caloric demand resulting from less physical activity. In some cases, negativity, such as anxiety or depression, contributes to poor appetite.
Healthgrades advises to contact a doctor immediately if a person experiences symptoms of serious dehydration, including fainting, confusion, lower urine output than usual or cold skin. Severe dehydration is a serious cause of appetite loss that may lead to irregular electrolyte levels, shock or coma if not treated promptly. Other accompanying symptoms requiring immediate medical attention include intense stomach pain, sudden loss of balance and high fever.