For many, they're a common occurrence.
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So why do bad dreams lurk in our subconscious?
Sleep psychologists tell us more about ordinary things that cause those extraordinary dreams.
Crafting nightmarish horror scenes is what actor/director Joe Burke excels at because he understands why people have them.
"It's usually about deep fears or anxieties or maybe losing loved ones, career," he said.
One in 20 people experience nightmares at least once a week. Many of these dreams feel real.
"All of these kinds of unresolved problems that we experience during the day can definitely cross over into our nightmare activity," said Cleveland sleep psychologist Dr. Alaina Tiani.
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And she added that watching frightening, hair-raising films can contribute.
"My sister makes me watch scary movies," said Daniella Tirado of Burbank.
Other causes? Something upsetting on the news or difficult conversations before bedtime.
Those with post-traumatic stress disorder may experience nightmares as well.
Alcohol, caffeine and side effects of certain medications can play a role too.
Tiani says focus on stress management and be mindful of the content you're consuming.
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"Anything stressful or overwhelming could set us up to potentially -- they may not cause nightmares but may heighten the risk," Tiani said.
Tiani said if your nightmares are frequent, recurrent and impact your quality of life, it's best to consult with a medical provider or mental health professional because different treatment options are available.
For the occasional nightmare, Daniella Tirado offers this advice:
"Don't watch scary movies. Workout, meditate, do something else rather than watch scary movies," she said.
But if you make films like Joe Burke, nightmares can inspire creativity.
"Write them down in a journal. If you have a nightmare just write it down and then turn it into a great screenplay and make a lot of money," he said.