Why do I dream so much, and is that good or bad?

Many people dream vividly, but that says little in itself. Dreaming happens mainly during what is known as REM sleep, a phase that everyone goes through several times every night. Whether that counts as 'too much' depends on what you experience: ordinary, sometimes bizarre dreams are normal. Only when dreams disrupt your sleep or daily life is there reason to look at them more seriously.

Frequent nightmares are more than unpleasant. Observational research shows they are an independent risk factor for suicidal thoughts and behaviour, even apart from insomnia. This is especially true in young people and at high nightmare frequency. Nightmares are also common in PTSD, where they are persistent and significantly disrupt sleep quality. Treatments are available: so-called IRT (a psychological approach in which you consciously rewrite the nightmare and rehearse it regularly) and the medication prazosin both reduce nightmare frequency and PTSD symptoms, albeit moderately. The combination of IRT with cognitive behavioural therapy for sleep problems produced the best results for sleep quality in a meta-analysis. If you have persistent nightmares due to trauma, discuss this with your GP or psychologist.

There is one situation that genuinely requires medical attention: when you physically act out your dreams, meaning you kick, hit or shout while sleeping. This is called REM sleep behaviour disorder. The majority of older adults with this problem eventually develop a neurodegenerative disease such as Parkinson's disease or Lewy body dementia. In addition, there is a direct safety risk: both you and your bed partner can sustain injuries. If you recognise this pattern in yourself or someone around you, see your GP.

Sleepwalking is another disorder in which dreaming and behaviour come together. About two to four percent of adults experience this. It increases the risk of injury and is associated with excessive daytime sleepiness and a lower quality of life. Finally, people with frequent migraines report significantly more unpleasant dreams and poorer sleep quality than people without migraines, and the more frequent the attacks, the greater this effect.