Ringworm is common, especially among children. But, it can affect people of all ages. It is caused by a fungus or yeast, not a worm like the name suggests.
Many bacteria, fungi, and yeast live on your body. Some of these are useful, while others can cause infections. Ringworm occurs when a type of fungus or yeast grows and multiplies on your skin.
Ringworm can spread easily from one person to another. You can catch ringworm if you touch someone who has the infection, or if you come into contact with items contaminated by the fungus, such as combs, unwashed clothing, and shower or pool surfaces. You can also catch ringworm from pets that carry the fungus. Cats are common carriers.
The fungus that causes ringworm thrive in warm, moist areas. Ringworm is more likely when you are often wet (such as from sweating) and from minor injuries to your skin, scalp, or nails.
Ringworm can affect the skin on your: