The occasional nightmare is considered a dream that’s simply more frightening or upsetting. Nightmares tend to be caused by stress, anxiety, or sometimes as a reaction to certain medications.
However, if you have nightmares frequently, you could have a sleeping disorder. Regularly occurring scary dreams can be labeled a sleeping disorder if the nightmares:
Many people experience occasional nightmares throughout their lives. However, the American Sleep Association estimates only about 5 percent of the population experiences persistent nightmares as a sleeping disorder.
Some factors that affect us when we’re awake can also influence our dreams.