Recurring dreams are dreams that re-appear with some pattern of regularity. 

Studies suggest that recurring dreams may contain more threatening content than regular dreams. Research suggests links between recurring dreams and psychological distress in both adults and children.

In lucid dreams, the dreamer is aware of the fact that he or she is dreaming, and often can manipulate or control the dream as it unfolds. 

Studies have found that lucid dreamers displayed significantly higher brain wave frequencies than non-lucid dreamers, as well as increased activity in parts of the frontal lobe. 

Research indicates that a majority of dreams contain content related to autobiographical memories—memories about the self—as opposed to episodic memories, which deal with events and details such as locations and times.

Daily life experiences don’t always present themselves in dreams immediately. Sometimes an experience from life will filter through to a dream after several days or even a week. This delay is what’s known as dream lag. 

Dreaming of these events—and the timing by which memories appear in dreams—may actually be an important part of the memory consolidation process.

Another function of dreaming appears to be processing and coming to terms with traumatic events. Grief, fear, loss, abandonment, even physical pain are all emotions and experiences that often replay themselves in dreams.