Depression
Weight loss may be a side effect of depression, which is defined as feeling sad, lost, or empty for at least two weeks. These emotions interfere with daily activities, such as going to work. Depression affects the same parts of the brain that control appetite. This can lead to poor appetite, and eventually, weight loss.
Endocarditis
Endocarditis causes inflammation of your heart’s inner lining, or endocardium. It develops when germs— usually bacteria — enter the bloodstream and collect in your heart. Most people with endocarditis have a fever. This may come along with a poor appetite. Elevated body temperature also increases metabolism and burns fat, causing weight loss.