Empty nails are not necessarily due to gray nails, but can also be caused by trauma or separation of the nail. Gray nails are a common fungal disease caused by fungal infection of the subdermal tissue, which can indeed lead to separation of the nail plate and nail bed, manifesting as empty nails, so when the nails are empty and accompanied by grayish yellow discoloration, cloudiness, and white spots, consider that you may have gray nails. However, other nail diseases can also lead to empty nails, such as trauma and nail separation disorder: 1. Trauma: If the patient has recently had trauma to the nail, it can lead to bruising under the nail, gradually separating the nail bed and nail plate, leading to gradual hollowing of the nail, which usually improves when a new nail is replaced, so don’t worry too much; 2. Nail separation disorder: If the nail is only empty inside, but the nail surface is smooth, then consider nail separation disorder. The cause of nail separation is not yet clear, but may be related to frequent nail picking and cleaning nail dirt. The nail growth process is affected by trauma, fungal infection and other factors, may lead to the phenomenon of empty nails occur, this situation, you should promptly seek medical examination, clear cause, and then treatment.