There are many different types of cancer, but they all cause the rapid spread of abnormal cells that disrupt your body’s systems. And because of the fast and intense process of cancerous cell division, a lot of your body’s energy stores are used. For that reason, unexplained weight loss may be one of the earliest signs of cancer.
Losing weight is most common in cancers of the stomach, esophagus, lungs, or pancreas. There are a few reasons that this happens. Part of it is the amount of energy that a growing tumor demands. But cancer may also promote muscle wasting or disrupt the hormones that regulate appetite.
Fever and fatigue are other early signs of cancer, but some cancers are asymptomatic in early stages.