Do you stop noticing a smell after breathing it for a long time?

Under normal circumstances, prolonged exposure to ordinary odors may lead to an inability to detect them due to olfactory adaptation. However, strong or fluctuating odors are less likely to become completely imperceptible. If concerned, it is recommended to seek medical advice in advance. Detailed analysis is as follows:

If breathing a common, stable-concentration odor (such as household perfume or food aroma), the smell typically becomes undetectable after continuous exposure for some time. This is due to the adaptive mechanism of the human olfactory system—when olfactory receptors in the nasal cavity are exposed to the same odor molecules over a long period, their sensitivity gradually decreases, weakening the odor signals received by the brain, resulting in the sensation of "not being able to smell." This is a normal physiological phenomenon.

However, if the odor is strongly irritating (such as paint fumes or disinfectant smell) or its concentration keeps changing (such as intermittently strong or weak cooking fumes), it is less likely to become completely imperceptible. Irritating odors continuously stimulate the olfactory nerves, making full adaptation difficult. Fluctuating odor concentrations repeatedly activate olfactory receptors, allowing the brain to continually detect the odor signal; therefore, a noticeable "inability to smell" does not occur. Some individuals may even experience discomfort due to the irritation.

When exposed to an odor for a prolonged period, regularly going to a well-ventilated area to breathe fresh air can help restore the sensitivity of olfactory receptors. Avoid long-term exposure to high-concentration irritant odors to reduce potential damage to the sense of smell. If sudden reduction or loss of smell occurs, seek prompt medical evaluation to rule out possible abnormalities in the olfactory system.