Sleep disorders, such as insomnia, sleep apnea, narcolepsy and restless legs syndrome can have a profound effect on quality of life. Sleep is such an essential part of our physical and mental health, it’s important to make sure any underlying conditions are being treated. Mild fatigue or sleepiness during the day may just be the result of poor sleep habits, or it could be a larger problem, such as insomnia or sleep apnea.