Warts are non-cancerous, benign growths on the skin that are caused by infection from viruses known as human papillomavirus (HPV). The most common type of warts include common warts, plantar warts (warts that appear on the soles of the feet), flat warts, and genital warts. Warts can present as rough, raised, hard bumps with tiny black dots or cauliflower-like growths. Warts are highly contagious and can easily spread by direct skin-to-skin contact or through contact with a contaminated object. Young children or people with weakened immune systems are most at risk for getting warts. Various treatment options for warts are available, ranging from at-home remedies to treatments done in a doctor's office.