There's a specific kind of fatigue that isn't going away even after a night's sleep. You sleep for 8 hours, then wake up, and yet you feel like you can't lie down. The majority blame stress, work, and weather. Many people don't think of blaming the sun. This is often the place where the problem really begins and is usually linked to a vitamin D deficiency. https://www.parcharmanch.com/blog/10-signs-of-vitamin-d-deficiency-you-shouldnt-ignore