Generally speaking, as dreams occur as a natural part of the sleep cycle, dreaming doesn’t affect the quality of sleep per se, however nightmares and especially recurring nightmares can be an exception to this. A nightmare, which is a dream characterized by negative, traumatic and scary feelings, can sometimes feel so intense that it wakes you up. Regular awakenings from nightmares, which leave you distressed, will have an impact on your sleep quality. However, even though nightmares may be common, a nightmare disorder (when nightmares occur with high frequency) is still rare.