A hard lump has developed on the sole of my foot, causing pain while walking. What's the reason, and what should I do?

Generally, a hard lump on the sole of the foot that causes pain while walking may be caused by conditions such as callus, insect bites, corns, plantar warts, or plantar fibromas. Management depends on the specific situation.

1. Callus: A callus forms when the skin on the sole of the foot is subjected to prolonged friction and pressure, leading to excessive thickening of the skin. It commonly occurs on pressure-bearing areas such as the heel and ball of the foot. It is recommended to wear properly fitting shoes and avoid overly tight, stiff, or high-heeled shoes to reduce friction and pressure on the soles.

2. Insect Bites: Insect bites on the sole of the foot may cause localized allergic reactions and inflammation, resulting in a raised, hard lump accompanied by tenderness. Usually, no specific treatment is required. If itching or pain becomes severe, washing the affected area with soap and water may help alleviate symptoms.

3. Corn: Corns typically develop due to long-term pressure or friction on the foot's skin, resulting in thickened skin. It is recommended to follow medical advice and consistently apply medications such as urea ointment or salicylic acid phenol plasters for treatment.

4. Plantar Wart: Plantar warts are a common foot skin condition caused by infection with the human papillomavirus (HPV). The virus enters through tiny breaks in the skin and multiplies beneath the skin's surface, causing benign skin growths. It is recommended to use medications such as imiquimod cream or fluorouracil cream under a doctor's guidance to remove the wart.

5. Plantar Fibroma: A plantar fibroma is a benign tumor arising from the plantar fascia, presenting as a round or oval, firm mass on the sole of the foot. Surgical excision under medical guidance is generally recommended. After surgery, adequate rest and avoidance of strenuous activity are advised.

It is recommended in daily life to wear comfortable and breathable shoes and socks to ensure foot comfort, and to avoid prolonged standing or walking to help prevent foot conditions.