What are Dreams? When, why and how they happen?

Dreams and Sleep Sleep is the most common fundamental activity of brain that helps to recover and re-energize the mind as well as the body. It is generally stated that humans spend one-third of their lives sleeping. A comfortable night sleep is characterized by absence of any voluntary movements with specific sleeping positions that minimize the sensory perception and regulated by internal biological clock synced with the circadian rhythm of the body.1 Dreams are a naturally occurring phenomenon in sleep that may or may not by recalled after waking up. It is a brain activity that varies with different phases of sleep and is considered as the least understood of all.

This article focuses on explaining the dreams, their types, when and how they happen, their functions, bad dreams and their management.

What are dreams?

Dreams have been studied from various perspectives such as psychoanalysis, psychological and neurosciences. They are series of episodes that happen during sleep and seem real during that time. Dreams are generally forgotten within minutes. A dream is the recall of mental activity that has occurred during sleep. They are one of Dreams and Sleep the most common but least understood activity of brain. During dreaming, bizarre thoughts and illogical sequences, sometimes followed by random experiences gathered during waking up period are observed. It is commonly observed during the REM phase of sleep except for night terrors, which are denoted as the sleeping disorder of NREM sleep. Various psychologists and philosophers have tried to explain the various activities and meanings of dreams. With recent research and updated technology, some experts suggest that dreams represent the recollection of events that have happened during the wakefulness as a critical mechanism in the formation of memories while others suggest dreams are just the result of some random brain activity.2

When and how do the dreams happen?

Dreams are the mental activity that occur during sleep. It is considered as the main activity for the episodic awakenings during the rapid eye movement REM sleep. With new research and technology, it to possible to Dreams and Sleep establish some answers like frequency, length and time of occurrence of dreaming. In a typical scenario, a person usually has four to five cycles of 90- minute sleep consisting of NREM and REM sleep, of which REM periods occupy approximately 20% of the night. Most of the dreaming happens during the REM phase of the 90 mins cycle. The individual REM cycles during a night’s sleep may last from few minutes to an hour, with the increase in length later at night. As we already know that dreaming coexists with REM phases of sleep cycle, the length of dreaming as subjectively experienced by the dreamer and objectively rated by the experiments, is in close association with the real time lengths of the corresponding REM sleep.3

Types of dreams

Recurrent dreams: Recurring dreams are the dreams that repeat more than once. The recurring revolves around the themes of confrontations, being chased, or falling. An underlying unresolved issue such as mental health condition, substance abuse or certain medications commonly causes these.4

Lucid dreams: Lucid dreams are the dreams during which the dreamer is not in deep sleep and knows that he or she is dreaming. The person is actively aware that they are dreaming. Vivid dreams involve more especially realistic or clear dreams.4

Nightmares: Nightmares or long, frightening dreams are the unpleasant episodes that causes awakening from Dreams and Sleep the sleep. Nightmares are vivid, terrifying nocturnal episodes that are more common in kids, especially from the ages of 3 to 6 years. Episodic awakening during the REM sleep due to nightmares are explained and described by patients in detail. The difficulty in returning back to sleep is commonly associated with patients with nightmares. The theme of dreams in lifelong nightmare sufferers are mostly associated with being chased or attacked. Nightmares because of trauma or stress event may lead to an interpersonal integration of the event. On the other hand, long-term or persistent nightmares can cause a decline in daytime functioning and performance.4

Effect of dreams on sleep:

A comfortable sleep is generally associated with better cognitive and emotional functioning of human mind. Dreaming is also considered as a normal part of healthy sleep. Studies have provided proofs of linking the dreams to efficient thinking, cognitive functioning, memory consolidation, learning and emotional processing. Hence, dreaming is described as a contributing factor for a better quality sleep. However not all dreams are considered healthy, nightmares or night terrors especially in childhood are generally traumatic and are associated with frequent awakenings and impaired quality of sleep.5

Effect of dreams on waking life:5

The effects of dreams on waking life are generally studied under three main topics:

1) Effect of nightmares on daytime: Studies have reported that nightmares or bad dreams affect the mood, reduce anxiety, concentration as well as the self-esteem on the following day. the most common contributing factor for Dreams and Sleep the daytime distress is the frequency of nightmares and the disrupted sleep.

2) Creative inspiration by dreams: Several studies have been conducted to assess the creative inspirations from dreams. In a large study with over 1000 participants about 7.8% of the participants reported recalling dreams as the creative aspect.

3) Dreams and psychotherapy: Modern psychotherapy is closely related to the study of dreams. Studies have reported improvement on insights and awareness after therapy session of interpreting dreams. The findings of different studies clearly indicate that there is not only continuity from waking life to dreaming but also from dreaming to waking life.

Functions of dreaming

Dreams are the most common and noticeable activity of brain with the individuals of every age group but the main purpose of dreams is still unclear. Some studies support the fact that dreams have no function. In contrast, some recent research has observed that dreams are the night-time continuation of the conscious thought process of the mind processing or reprogramming the thoughts of the central nervous system for the proper functioning and performance for the next day’s conscious functioning. Evidence from various studies have also supported the fact that like all other physiological functions of the body, dreaming is also important for learning and memory consolidation for a person for well-functioning of the person’s mental, emotional and physical state of mind.6

Can you remember dreams?

The ability to recall and recite the dreams reflects the accessibility or distance from awake thought. The electroencephalographic patterns that depict the most wake states seem to show highest recall rates for the Dreams and Sleep dreams while sleeping. Recent studies of dreams have revealed that about 65% of the dreams are associated with sadness, apprehension, or anger; 20% with happiness or excitement; and, somewhat surprisingly, only 1% with sexual feelings or acts.7 Studies have reported that the content of the dreams varies with the stage of sleep. Dreams tend to be more clear with bizarre details and storyline are reported during the REM phase of sleep. In contrast, dreams experienced during NREM or deep sleep are more diffuse like dreams about colors or an emotion. The dreams reported during 1 and 2 stages of sleep are generally shorter, simpler and have very less connections in comparison to dreams during the REM sleep. The content of dreams explained by the individuals is based on the sleep stage from which they are awakened.6

Management of bad dreams and nightmares:8

Proper diagnosis and education of family members about nightmares and night terrors are important components of management. Lifelong nightmares and night terrors are commonly observed in children and are usually disturbing for the parents and other family members. The management of nightmares involves the control of environment by removing sharp, dangerous objects and providing barriers to prevent escape from the safe space. Reassurance and support of patient and parents plays an important role in the therapy as this disorder usually disappears with maturity. Pharmacological management of nightmares is usually not indicated and in fact, it should be discouraged because it may lead to further disruption in quality of sleep behavioral modifications with lifestyle changes acts as an effective method for the management of nightmares and night terrors in older children and young adults. Studies have reported a successful short and long-term reduction of nightmares in more than Dreams and Sleep 70% of the patients. Behavioral modifications as a management tool include:

  • Follow a proper sleep schedule that includes sleeping and waking up around same time even on weekends
  • Avoid exercise in the evenings close to bed-time, in fact it is better to work-out during the day to allow body and mind to calm down before going to bed.
  • Avoid intake of stimulants such as alcohol and cigarettes just before bed
  • Avoid watching scary, distressing or stimulating content provoking negative thoughts before bed time
  • Keep your sleeping environment calm and cooler that can help in early onset of sleep


Sleep is the most important basic mechanism of human brain to revive and reenergize the mind and body. Although the mechanism and functions of dreams is still a mystery but they are commonly found as an important contributing factor for the continuation of the thought process of the conscious mind, as well as for performance, learning, memory and emotional processing of the brain. Dreaming is considered as a healthy activity of brain. The content and frequency of dreams is associated with the quality of sleep and the activity on the following day.


Q1. What are dreams?

A2. Dreams are the mind activities that are experienced during sleep. They are reported by the subjects and experienced through the sleep studies as thoughts, images and emotions expressed while sleeping. Dreams and Sleep

Q2. Why do we dream?

A2. There are several theories that tried to explain the reasons for dreams but the existence of dreams is still a mystery and an on-going research. Some researchers believe that dreams have no role, on the other hand some authors believe that sleep serve to the process of intense emotions and helps in learning and memory consolidation.

Q3. How long does a dream last?

A3. There is no definite answer to this question. The length of dreams may vary from seconds to minutes. Dreaming usually happen during the REM phase of sleep cycle, hence the length of dreaming also varies with the varying duration of REM sleep throughout night.

Q4. Are dreams influenced by fear and anxiety?

A4. Dreams are highly influenced by the activities of day time. They are often expressed as current concerns and situations. They can be negative such as fear or pre-exam anxiety but can be positive also like dreaming about your favourite sport or places one’s willing to go.

Q5. What are lucid and vivid dreams?

A5. Lucid dreams are the dreams during which the dreamer is not in deep sleep and knows that he or she is dreaming. The person is actively aware that they are dreaming. Vivid dreams involve more especially realistic or clear dreams.

Q6. What are nightmares?

A6. In common terms, a nightmare is a bad dream that causes a person to wake up from the sleep. They can be Dreams and Sleep scary, threatening or bothersome for the person, they are normal unless they start interfering with the sleep quality and activities during the daytime.

Q7. Do dreams affect sleep?

A7. Dreaming is a part of healthy sleep and is considered completely normal without any negative impact on sleep in most of the cases. However, nightmares on the other hand involve frequent awakenings from the sleep that can cause insufficient or poor quality sleep. The continuous sleep deprivation can lead to other health issues.

Q8. How can you manage nightmares?

A8. Individuals with frequent nightmares more once a week should be diagnosed whether they have nightmare disorder. The main management for nightmare involves talk therapy to reduce the anxiety or underlying fear. Another method to reduce nightmares involves the practice of sleep hygiene including following a proper sleep schedule, maintaining a calmer and quieter sleep environment, exercising and limiting intake of stimulants before bed.


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  2. Hobson JA, Pace-Schott EF. The cognitive neuroscience of sleep: neuronal systems, consciousness and learning. Nat Rev Neurosci. 2002;3(9):679-93. doi: 10.1038/nrn915.
  3. Eiser AS. Physiology and psychology of dreams. Semin Neurol. 2005;25(1):97-105. doi: 10.1055/s-2005-867078.
  4. Revonsuo A. The reinterpretation of dreams: an evolutionary hypothesis of the function of dreaming. Behav Brain Sci. 2000;23(6):877-901; discussion 904-1121. doi: 10.1017/s0140525x00004015.
  5. Schredl M. Characteristics and contents of dreams. Int Rev Neurobiol. 2010;92:135-54. doi: 10.1016/S0074-7742(10)92007-2.
  6. Pagel JF. Nightmares and disorders of dreaming. Am Fam Physician. 2000;61(7):2037-42, 2044.
  7. Purves D, Augustine GJ, Fitzpatrick D, et al., editors. Neuroscience. 2nd edition. Sunderland (MA): Sinauer Associates; 2001. The Possible Functions of REM Sleep and Dreaming. Available from: https://www.ncbi.nlm.nih.gov/books/NBK11121/
  8. Hasler B, Germain A. Correlates and Treatments of Nightmares in Adults. Sleep Med Clin. 2009;4(4):507-517. doi:10.1016/j.jsmc.2009.07.012

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