Sleep is essential for your physical health and emotional wellbeing. Everyone experiences occasional sleep problems, but if you experience sleep problems repeatedly, it could indicate an underlying health problem. Sleep disorders are problems associated with sleeping, including difficulty falling or staying asleep through the night, feeling sleepy during the day, or waking up feeling exhausted. Because of lack of sleep you may find it difficult to concentrate and perform activities of daily living. This lack of sleep can lead to depression, mood swings, or other health problems.