Hanahaki Disease (花吐き病 (Japanese); 하나하키병 (Korean); 花吐病 (Chinese)) is a fictional disease where the victim coughs up flower petals when they suffer from one-sided love. It can be cured through surgical removal, but when the infection is removed, the victim's romantic feelings for their love also disappear.

The trope was popularized in East Asian fandoms (Korean, Japanese, Chinese) before it was used by Westerners. In fandom, it is used almost exclusively for BL.