Is it normal to sense the presence of someone who died?
Yes. Sensing the presence of someone who died, hearing their voice, glimpsing them, or feeling them nearby is a common bereavement experience rather than a sign of mental illness. In Rees's widely cited study of widowed people in Wales, close to half reported such experiences, and most found them comforting.
People rarely admit this one out loud. They worry it means grief has tipped into something clinical. Almost always it does not, and the silence is the only genuinely unhelpful part.
What the research found
The landmark work is W. Dewi Rees's 1971 study, published in the British Medical Journal, which interviewed hundreds of widows and widowers. Close to half reported hallucinatory or illusory experiences of their dead spouse: a sense of presence most often, sometimes hearing, seeing, or being spoken to. Crucially, these experiences were more common in people whose marriages had been happy, they were usually described as helpful, and they were not associated with mental illness. Later reviews of post-bereavement sensory experiences have repeatedly found the same pattern across cultures.
Why it happens
The brain spent years building a model of the world with that person in it: their step in the hallway, their voice pitched under other voices, the shape of them in a doorway. Bereavement means updating an enormous model, and while it updates, the old expectations keep firing. That is why the experiences cluster around familiar places and habitual times, and why they tend to soften as the model catches up with reality.
Comfort, and the reason we do not manufacture it
Many bereaved people describe these moments as steadying, a felt continuation of the bond rather than a break with reality. Research on continuing bonds broadly supports connection carried in memory and identity. The same literature distinguishes that from relating to the person as still concretely present and interactive, which travels with poorer adjustment. Spontaneous experiences arriving unbidden are one thing. Engineering an interactive version of someone who died is another, which is why we will not simulate the dead.
When it is worth a conversation with a doctor
The line is not the experience; it is distress and impairment. Talk to a professional if the experiences frighten you, if you are losing track of what is real, if they come with disorganized thinking, or if they are getting in the way of eating, sleeping, working, or caring for people. Also worth mentioning: severe sleep deprivation makes odd perceptual experiences much more likely, so if you are barely sleeping, start with sleep.
If it happens to you
You are allowed to simply have it. You do not have to interpret it, defend it, or explain it to anyone who will make it small. Telling one safe person is often enough to lift the private worry that something is wrong with you.
See also: Rees (1971) British Medical Journal, on the hallucinations of widowhood; Castelnovo et al. (2015), review of post-bereavement hallucinatory experiences; Klass, Silverman & Nickman (1996) Continuing Bonds; Field, Gao & Paderna (2005) Death Studies.