Love and a cough cannot be hid.

Strong affection may seem to reveal itself despite attempts at concealment, through expression, attention, or altered behavior. Like a cough, it is portrayed as breaking through restraint and becoming noticeable to others.

The saying also suggests that inward feelings can have outward signs. It is a figurative observation, not a dependable way to determine whether someone loves another person: emotions may be hidden, and visible behavior can have more than one interpretation.

Use it lightly when romantic attachment seems obvious despite denials or apparent indifference, in teasing, affectionate conversation, or reflective writing. Avoid treating it as proof of another person’s feelings or intentions, especially where comments on private feelings could feel intrusive.