Thick toe caps are considered to be ageing, trauma, gray nails and so on. 1. Ageing: With age, the body’s metabolic rate will slow down, and the local cuticle will accumulate at the nail, resulting in a thickening of the nail. 2. Trauma: If there is a trauma in the toe cap area, it will lead to deformation of the toe cap, which may also lead to thickening of the toe nails, but with the growth of the nails, the newly grown nails will return to normal. 3. Gray nails: gray nails, also called onychomycosis, are nail lesions caused by dermatophytes that invade the nail plate and nail bed, and most of the patients will be accompanied by tinea pedis, which mainly manifests itself as cloudy, thickening, separation, discoloration, buckling, and unevenness of the lesion toenails. There may be other reasons for the thick toe cap, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.