A fungal culture test helps diagnose fungal infections, a health problem caused by exposure to fungi (more than one fungus). A fungus is a type of germ that lives in air, soil and plants, and even on our own bodies. There are more than a million different kinds of fungi. Most are harmless, but a few types of fungi can cause infections. There are two main types of fungal infections: superficial (affecting parts of the outer body) and systemic (affecting systems inside the body).Superficial fungal infections are very common. They can affect the skin, genital area, and nails. Superficial infections include athlete's foot, vaginal yeast infections, and ringworm, which is not a worm but a fungus that can cause a circular rash on the skin. While not serious, superficial fungal infections can cause itchy, scaly rashes and other uncomfortable conditions. A fungal culture test is used to find out whether you have a fungal infection. The test may help identify specific fungi, guide treatment, or determine if a fungal infection treatment is working.