While we think of sleep as a time for recharging the body, the brain is actually quite active during sleep — dreaming. Our dreams can be soothing or scary, mysterious or helpful, and realistic or fantastical.

Sometimes we wake up and have no idea that we’ve dreamed, while other times, we can closely recall our dreams because they were so intense. These are known as vivid dreams.

Brain scientists aren’t sure why humans dream in the first place, but they think it has something to do with memory.

Dreaming might help the brain eliminate any unnecessary information or memories while processing and storing what’s important. Some people feel more refreshed after having had slept and dreamed, even if they do not remember dreaming.

People are most likely to remember the last dream they’ve had in their sleep cycle. But it’s possible to remember a vivid dream long after it’s occurred if it seemed very intense.

Vivid dreams can be positive or negative, realistic or fantasy. Scientists know that most heavy dreaming occurs during rapid eye movement (REM) sleep. REM sleep normally cycles every 90 minutes during a night of sleep and may last 20 to 25 minutes.

About 25 percent of an adult’s night of sleep is spent in REM cycles. The average adult should get between seven and nine hours of sleep per night for optimal health. That’s a lot of time for dreaming!

So, what causes vivid dreams? Scientists aren’t completely sure. But they think the following factors may play a part.

Stress or anxiety

Difficulties real and imagined can cause a person to experience stress and anxiety in their daily life. Problems with friends, family, school, or work can trigger intense dreams as can big events like getting married or buying a house.

Stressed caused by traumatic events, such as a death of a loved one, sexual abuse, or a car accident can also cause vivid dreams. Anxiety, in particular, is associated with an increased risk of disturbing and intense nightmares.

Sleep disorders

Sleeping issues that cause a lack of sleep, such as insomnia and narcolepsy, can increase one’s risk of experiencing vivid dreams.

Changes to your sleep schedule, such as flying overseas (and going to sleep at a different time) or getting less sleep than usual, can also increase this risk.

Medications

There are some medications that have been reported to contribute to vivid dreams. These medications include many antidepressants, beta blockers, blood pressure medications, Parkinson’s disease drugs, and drugs to stop smoking.

Substance abuse

Using alcohol in excess, using recreational drugs, or experiencing a withdrawal from drugs can trigger vivid dreams, often nightmares.

Other health disorders

In addition to stress and anxiety, other mental health conditions, such as depression and schizophrenia, are associated with vivid dreams. Physical illnesses, like heart disease and cancer, have also been associated with vivid dreams.

Early pregnancy

Pregnancy can trigger changes in the body’s hormone levels, sleep patterns, and emotions. Many pregnant women say they experience vivid dreams, especially during the early days of their pregnancy.

Normally, vivid dreams are nothing to worry about. Sometimes they may only affect you during a certain part of your life.

But negative vivid dreams, especially if they last for weeks or months, can be emotionally disturbing and disruptive to your sleep. And that can cause health problems.

Some common side effects of vivid dreams include:

  • Daytime sleepiness. This can cause concentration and memory problems that can affect your productivity at school or work. It can even affect your ability to carry out everyday tasks, such as driving or taking a shower. Even the smallest tasks can become dangerous if you get distracted.
  • Mood problems. Vivid dreams can be emotionally draining, causing depression or anxiety symptoms. This can be an especially concerning problem if your vivid dreams persist over time.
  • Resisting sleep. You may find that you consciously or subconsciously avoid going to bed or falling asleep because you fear you’ll have another bad dream.
  • Suicidal attempts or thinking. Some people have reported suicidal thoughts (ideation) secondary to troubling dreams. This is extremely serious. If you have attempted or are considering suicide, get help from a crisis or suicide prevention hotline. Try the National Suicide Prevention Lifeline at 800-273-8255. It’s important to get help right away.

It isn’t always possible to pinpoint an exact cause of vivid dreams. In many cases, these dreams will go away over time.

But if your vivid dreams are causing you emotional distress or physical problems, you might benefit from medical treatment or lifestyle modifications.

Schedule an appointment with your doctor or a sleep specialist to try to determine what treatments or lifestyle modifications are right for you.

Here are some of the common treatments for vivid dreams.

Medical intervention

If your vivid dreams are caused by an underlying mental or physical health condition, you can reduce your risk of vivid dreams by treating that condition.

Staying healthy

Eating well, maintaining a healthy weight, getting enough sleep, maintaining a regular sleep schedule, drinking enough water, and looking after your mental health can help prevent vivid dreams.

Coping with stress and anxiety

Everyone experiences stress and anxiety, but some people are better at coping with it than others. If you feel that your stress and anxiety levels are out of control, you might want to consider:

  • meditation
  • deep breathing
  • relaxation techniques
  • art therapy
  • exercise
  • other activities that can ease your stress

Another major thing you can do is to make sure you always reserve some time for relaxation during the day so you don’t feel overwhelmed. A racing mind can result in vivid dreams and sometimes nightmares.

Imagery rehearsal therapy

This treatment is often used for people experiencing vivid dreams, especially nightmares, as a result of trauma. This therapy, done with a mental healthcare professional, involves changing the ending to a nightmare you remember when you’re awake until it no longer becomes threatening.

Your mental healthcare provider will ask you to continue playing over the new, nonthreatening ending to the dream in your mind. This therapy is designed to reduce a person’s frequency of vivid dreams — especially nightmares.

Medication

Most doctors don’t recommend use of medication to treat vivid dreams. However, in the case of nightmares induced by trauma, such as post-traumatic stress disorder, a doctor may consider prescribing sleeping medication or anti-anxiety medication to help induce sleep.