Again, this symptom isn’t straight forward, making it harder to pin to colorectal cancer. Fatigue can be caused by poor diet, lack of sleep, excess or lack of physical activity, and medication.
It may also be a sign of more serious conditions like anemia, acute liver failure, diabetes, heart disease, hypothyroidism, and much more. However, being constantly tired, even when you eat and sleep well and have a clean bill of health, may be a sign of colorectal cancer.
Cancer cells require plenty of energy, which means that there’s less to go around for healthy cells. Colon cancer can also cause bleeding, further starving your body of oxygen and nutrients.