Guide

Checking

Checking behaves differently from other compulsions in one important way: doing it repeatedly makes your memory of having done it worse, which is why the tenth check feels less convincing than the first.

Reviewed by Albert Wong, PhDClinical psychologistLast reviewed September 2026About this site

Checking compulsions are driven by responsibility rather than by disgust. The fear isn’t that something bad will happen but that it will happen because of you — because you left it on, left it open, sent it wrong, hit someone and didn’t notice.

What gets checked

Locks, stoves, taps, plugs, windows. Emails and messages, reread before and after sending. Work, checked for an error that will cost someone. The road behind you after a bump — hit-and-run checking, which sends people back around the block or watching local news, and which overlaps substantially with harm themes.

And bodies: checking your own for symptoms, which shades into health-focused OCD.

Why checking makes it worse in a specific way

This is the finding worth knowing. Repeated checking has been shown experimentally to reduce memory confidence, memory vividness, and memory detail — not to improve them. The more times you check the stove, the less certain your recollection of having checked becomes.

The mechanism appears to be that a repeated, familiar action stops being encoded distinctly. The tenth check blurs into the ninth. So the compulsion actively manufactures the doubt it exists to resolve, which is why people end up checking for an hour and leaving the house less sure than when they started.

This isn’t offered as reassurance. It’s offered because knowing the mechanism makes response prevention make sense rather than feel arbitrary.

The mental version

Much checking is internal.Reviewing a memory of having locked the door rather than going back. Replaying a conversation for anything incriminating. Checking a past event to establish what happened — which is real event and false memory territory.

Treatment

ERP, with response prevention shaped to the ritual. Typically: check once, normally, with attention — and then leave, and don’t return, and don’t review it mentally, and do not ask anyone.

Clinicians usually build in the deliberate uncertainty: leaving without checking at all, or leaving something genuinely ambiguous, so that you practise carrying the not-knowing rather than resolving it.

A common trap is substituting one check for another — photographing the stove instead of returning to it, or asking a partner to confirm. Both are the compulsion in a new outfit, and both need to go.

The responsibility question

Underneath most checking is an inflated sense of personal responsibility: if something bad happens and you could conceivably have prevented it, that’s on you. Some clinicians address this directly alongside the exposures, and inference-based CBT is particularly interested in it. It isn’t a substitute for the exposure work, and it’s often what makes the exposure work make sense.

Keep reading

43 guides on OCD and ERP, free and without an account. There is a directory here too — it is new, and growing.

General information, not clinical advice; the people described are composites, not real clients. If you notice yourself reading this page to make a feeling go away, that is the loop, and the answer is not another article. Listings on this site are maintained by independent practices. If you are in immediate danger, call 911; the 988 Suicide & Crisis Lifeline is available by call or text any time.