What counts as a pre-existing condition on travel insurance?
Broadly, any medical condition you have had before buying the policy — and the definition is far wider than most travellers assume, which is why this is the leading cause of declined travel claims.
What typically counts:
Any condition for which you have received treatment, medication, tests or consultation, commonly within the last two to five years depending on the insurer's wording.
Any condition you are waiting to investigate — awaiting test results or a specialist appointment counts, even without a diagnosis.
Controlled conditions still count. Well-managed asthma, high blood pressure controlled by medication, or diabetes in good control are all pre-existing conditions requiring declaration. People routinely assume "under control" means "not relevant", and it does not.
Past conditions, sometimes including ones resolved years ago, depending on wording.
Conditions of someone else in some circumstances — a relative not travelling whose illness might cause you to cancel, and whose condition may need declaring for cancellation cover.
Why this matters so much. Undeclared conditions can void the entire policy or lead to a refused claim, and the claim need not relate to the condition in some wordings. Medical treatment abroad, particularly in the United States, and repatriation can run to six figures. This is the single largest financial risk in ordinary travel.
How declaration works. Most insurers run a medical screening process, online or by phone, asking structured questions. The outcome is usually one of: covered at standard price, covered with an additional premium, covered with that condition excluded, or declined.
Being excluded is not always fatal — cover for everything else remains — but understand what is excluded before travelling.
Practical points: declare everything and let the insurer decide relevance; if a condition changes or you are diagnosed after buying, tell them, since policies require notification; and specialist insurers exist for serious conditions where mainstream providers decline.
Check whether an EHIC/GHIC applies — it is not a substitute for insurance.