Why is there a bad smell under the fingernails?

An unpleasant odor in the fingernail grooves may result from various causes. The spaces around the nails easily accumulate debris such as dead skin cells and dust, which can foster bacterial growth in moist environments, leading to an unpleasant smell. Improper nail trimming—such as cutting nails too short or unevenly—can cause the nail edges to grow into the surrounding skin, resulting in ingrown nails. This condition further increases the risk of bacterial proliferation and subsequent odor. Poor personal hygiene habits, such as infrequent handwashing or irregular nail trimming, can exacerbate bacterial buildup in the nail folds, making the odor more pronounced. To prevent odor formation in the nail grooves, it is recommended to maintain good personal hygiene, regularly trim nails, and clean them properly using suitable cleansing agents.