What are some of the causes of weakness and loss of energy?

Weakness and loss of energy are frequent complaints made by individuals who may have physical disease. These complaints may also be found in patients who are profoundly depressed.

 In cases where there is suspected physical disease, careful medical evaluation is warranted in order to rule out multiple sclerosis, stroke, diabetes, cancer, anemia, kidney or liver disease, muscle disease, and disorders of peripheral nerves such as Guillain-Barre Syndrome. Many of these causes are treatable if discovered early enough, so seeing a physician in a timely fashion is strongly encouraged.