Ringworm in adults is caused by a fungal infection. The fungi that cause ringworm thrive in warm and humid areas such as locker rooms, public showers, and soil. Ringworm is contagious and can be spread in several ways, including:

• Human to human: Ringworm often spreads by direct, skin-to-skin contact with an infected person.
• Soil to human: In rare cases, ringworm can be spread to humans by contact with infected soil.
• Object to human: The fungus that causes ringworm can linger on surfaces, clothes, towels, and in combs and brushes.

People who live in warm climates, have close contact with an infected person or animal, share clothing, bedding, or towels with someone who has a fungal infection, or participate in sports that feature skin-to-skin contact are at higher risk of getting ringworm. Sweating a lot in the groin area can also lead to jock itch, a type of ringworm. To prevent ringworm, it is important to practice healthy and hygienic behaviors such as washing your hands after interacting with an animal, disinfecting and cleaning pet living areas, limiting contact with people or animals with ringworm if you have a weakened immune system, wearing shoes if showering or walking in community areas, not sharing personal items like clothing, towels, or hairbrushes with people who might have ringworm, changing your socks and underwear at least once a day, and keeping your skin clean and dry.