A fungal infection occurs when harmful fungi invade the body, leading to various health issues. These infections can affect the skin, nails, or internal organs, and are often caused by common fungi found in the environment. Symptoms may include redness, itching, and swelling, depending on the infection's location. Common types of fungal infections include athlete's foot, ringworm, and thrush. People with weakened immune systems or underlying health conditions are more susceptible to these infections. Treatment typically involves antifungal medications, which can be topical or oral, depending on the severity and type of infection.