Warts are benign skin hyperplasias that look like colorless moles.  Warts appear in the upper layers of the skin due to a virus belonging to the family of human papillomaviruses (HPV). This family of viruses includes over 150 strains. Some of these viruses cause warts and others genital warts.

The virus causes a rapid proliferation of skin cells, resulting in lumps that are more annoying than dangerous, however, they are highly contagious.

The virus that causes the wart is transmitted by contact and affects solely humans; it cannot be transmitted to animals. Wart is transmitted by direct skin contact or by touching wet surfaces, such as swimming pools and changing rooms, which have been infected by people who already have warts. Children and adolescents are more likely to become infected because they have not (yet) developed antibodies against the virus and are more likely to come into contact with people suffering from warts. Warts usually appear on the hands and feet, but they may also develop in other parts of the body such as the face.

Although it is a benign condition, warts cause concern to patients as they may be accompanied by severe pain, itching or bleeding, and if found on the feet, they can make walking difficult.