Fingernail rotten consideration and nail trauma, nail fungus, nail groove inflammation, psoriasis and other related. 1. Nail trauma: when the fingernail area suffers from external impact or injury, it can be infected or improperly handled, resulting in rotten fingernails. 2. Nail fungus: Nail fungus is caused by infected skin fungus, such as red trichophyton, candida and so on. Early symptoms of patients are nail color change, brittle nails or easy to separate, with the progress of the disease, the causative agent damage to the nail plate and other parts, can be manifested as finger nail rot, nail bed abnormal thickening and so on. 3. Inguinitis: Inguinitis is related to excessive nail trimming and long-term contact with irritants. The patient mainly manifests as redness, swelling and pain in the tissues around the nail, and in serious cases, it will turn into pus, thus manifesting as rotten fingernails. 4. Psoriasis: the etiology of psoriasis is not clear, it may be caused by genetic factors and environmental factors. When psoriasis involves the skin of the hand, it can be manifested as erythema of the skin, itching or pain, and may also rupture, hemorrhage, hyperkeratosis under the nail, nail separation and other symptoms, which is manifested as rotten fingernails. It is recommended that the person with rotten fingernails should consult a doctor for examination and treatment after clarifying the cause of the disease, and should not use drugs indiscriminately. Pay attention to the daily care of the hands, avoiding foreign body friction and stimulation.