Phototherapy is a medical treatment that uses light to help improve various skin conditions and mood disorders. It involves exposing the skin to specific wavelengths of light, which can reduce inflammation and promote healing. Commonly treated conditions include psoriasis, eczema, and vitiligo. In addition to skin issues, phototherapy is also used to treat seasonal affective disorder (SAD) by mimicking natural sunlight. This can help boost mood and energy levels during darker months. Overall, phototherapy is a safe and effective option for many people seeking relief from certain health problems.