Quick answer
Déjà vu is the feeling that a current experience is strangely familiar, even though you recognize that it should be new. Occasional brief episodes can happen in otherwise healthy people. Researchers are still studying why the feeling occurs.
What might explain the feeling?
One area of research concerns the systems involved in familiarity and remembering. A situation may feel familiar without a clear memory explaining why, but no single theory accounts for every episode. Research involving people with temporal-lobe epilepsy has helped scientists study memory networks; its findings should not be used to assume that an ordinary episode is a seizure.
A review of research on déjà vu and memory networks describes hypotheses involving temporal-lobe structures and acknowledges that the mechanisms are still being investigated.
Is déjà vu connected to dreams?
A place or event can remind someone of a remembered dream, and some people describe feeling that they dreamed a situation before. That personal impression does not prove that a dream predicted the event or that all déjà vu comes from dreams. Familiarity and memory are complex, and the cause of an individual episode may be unclear.
Dreams can occur during both REM and non-REM sleep. Read our guide to types of dreams for more on dream recall and sleep stages.
Related experiences
- Jamais vu: a familiar situation or word briefly feels unfamiliar.
- Tip-of-the-tongue: feeling that you know a word or name but cannot retrieve it at that moment.
- Déjà rêvé: a feeling that a current experience resembles something previously dreamed.
These terms describe different experiences. None, on its own, establishes a medical diagnosis or a supernatural explanation.
When to talk with a clinician
Occasional brief déjà vu is usually not a reason to panic. Seek medical advice if episodes are frequent, prolonged, changing or accompanied by confusion, loss of awareness, unusual sensations or movements. A clinician can assess the full picture. Cleveland Clinic’s overview describes how déjà vu can sometimes occur as part of a temporal-lobe seizure.
Frequently asked questions
Does déjà vu mean I dreamed the future?
No. Feeling a match with a dream does not demonstrate that the dream predicted an event.
Can dreams happen outside REM sleep?
Yes. Dreams can occur during non-REM as well as REM sleep.
Is déjà vu always a seizure?
No. Occasional brief déjà vu can occur in healthy people. Frequent episodes or episodes with loss of awareness or other symptoms deserve medical evaluation.
What is jamais vu?
It is the experience of something familiar briefly feeling unfamiliar.
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