3. Depression 
Depression can strike at any time and is closely linked with chronic fatigue. Depression happens when someone feels anxious, sad or experiences feelings of hopelessness for long periods of time. One of the major side effects of depression is sleep issues. The sleep issues are typically categorized as insomnia or sleep apnea. If you’re suffering from depression, you may feel tired even if you’re not exerting much energy during daily tasks.
Taking control of fatigue by practicing deep-breathing exercises, stretching and yoga can ease sleepiness-related depression symptoms. Sometimes depression can be fixed by developing a routine, such as going to bed the same time every night, steering clear of naps, and turning off electronic devices before bed.