A fungal infection is an illness caused by the overgrowth or invasion of fungi on the skin, nails, mucous membranes, or internal organs. Common superficial infections include athlete’s foot, ringworm, nail fungus, and yeast infections, which often present with itching, redness, scaling, or thickened nails. These infections typically thrive in warm, moist environments and can spread through direct contact or contaminated surfaces. In individuals with weakened immune systems, fungi can cause more serious systemic infections affecting the lungs, bloodstream, or other organs. Treatment depends on the location and severity and may involve topical or oral antifungal medications. Maintaining good hygiene, keeping skin dry, and addressing underlying health conditions can help prevent recurrence.