Nail fungus is caused by dermatophytes, a group of fungi that thrive in warm, moist environments. In some cases, yeasts and molds can also contribute to the infection. The condition usually begins as a white or yellow spot under the tip of the fingernail or toenail. As the infection spreads deeper, it may cause the nail to discolor, thicken, and crumble at the edge. https://zanaquick.com/collections/frontpage