The fingernail cap protrudes out, which may be caused by physiological factors such as heredity, or pathologic factors such as onychomycosis, malnutrition, and so on. 1. Physiological factors: if family members have prominent fingernails, they may be affected by genetic factors, and the nails themselves are not particularly flat, and may be high or low. 2. Onychomycosis: Onychomycosis is a disease caused by dermatophytes invading the nail plate and subnail tissues, with symptoms such as thickening of the nail plate and uneven surface, which leads to protruding finger caps. 3. malnutrition: if you don’t pay attention to nutritional supplementation, long-term partiality, picky eating, weight loss, resulting in a variety of trace elements, vitamin deficiency, will have an impact on the growth of the nails, resulting in fingernail caps protruding. There are other reasons for the protruding fingernail caps, so it is recommended to consult a doctor in time to clarify the cause and follow the doctor’s instructions for standardized treatment.