Oxyosmia is a heightened or abnormally sharpened sense of smell, the olfactory counterpart to oxygeusia for taste. It can arise during pregnancy, in migraine aura, with certain medications, or in neurological conditions, and it makes everyday odours, cooking smells, perfumes, cleaning products, intensely vivid or even nauseating. For pregnant women, oxyosmia combined with nausea helps explain the sudden food aversions of the first trimester. In the food world, professional tasters and flavourists cultivate acute olfaction through training, though theirs is discrimination rather than raw sensitivity. Heightened smell has practical consequences for eating: since retronasal olfaction provides most of what we call flavour, oxyosmia can make meals overwhelmingly intense or trigger aversions that narrow the diet, occasionally to nutritionally significant degrees.