There are more than 80 individual sleep disorders, but they are divided into 4 main categories:
Dyssomnias, in which there is insomnia (difficulty initiating or maintaining sleep), sleepiness during the day, and abnormal sleep-wake timing; examples include sleep apnea and the effects of medications or alcohol
Dyssomnias, in which there is insomnia (difficulty initiating or maintaining sleep), sleepiness during the day, and abnormal sleep-wake timing; examples include sleep apnea and the effects of medications or alcohol
Parasomnias, in which there is abnormal behavior around sleep, but without excessive sleepiness or insomnia; examples include sleepwalking or night terrors
Medical-psychiatric sleep disorders, in which a condition that causes other problems disrupts or impairs sleep; examples include anxiety, depression, Parkinson’s disease, dementia or gastroesophageal reflux disease (GERD)
Sleep problems that cannot be clearly separated from normal variation, or for which there is no consensus among experts; examples include pregnancy-associated sleep disorder and sleep hyperhidrosis (excessive and unexplained sweating during sleep)
