The hard white stuff on the feet is mostly related to corns, calluses and plantar warts. 1. Corns: The formation of corns is related to the excessive proliferation of the cuticle triggered by long-term mechanical stimulation of the foot skin by friction and pressure. The clinical manifestation is that the skin surface is flat or elevated, the skin is thickened, and there is a clear cuticle proliferation, which is white or yellowish. 2. Callus: it occurs in the palm of the hand, the sole of the foot, there will be flat or raised thickened plaque, hard to touch, yellowish-white. The cause of the disease may be related to occupation, foot deformity, and overgrowth of the skin stratum corneum. 3. metatarsal warts: mostly caused by human papilloma virus infection, low immunity, trauma, barefoot walking and other factors may also trigger metatarsal warts. The main symptom is localized hyperkeratosis, rough plaque, some patients will appear on the feet with white hard objects. There are many reasons for white hard objects on the feet, so it is recommended that the patient seek medical examination to clarify the cause of the disease and actively treat it.