Dealing with common illnesses like coughing, sneezing and nausea can be irritating, but pretty simple manage their symptoms. These common illnesses are easy to explain and take care of. It’s when you have a symptom that does not make sense that you and the medical community scratch your collective heads and try to make sense of what is happening. One of the most misunderstood symptoms known to man is chronic fatigue. Being tired due to work or long hours awake is understandable. If you always feel like you have a lack of energy and have no idea why, it’s a bitmore frustrating. Some of a few reasons why a lack of sleep may be interfering with your life include: having sleep disorders, stress and anxiety, and disorders like fibromyalgia.