Gray nails are a common fungal disease caused by a fungal infection of the nail plate and the underlying nail tissue. In fact, in the early stages, the symptoms of gray nails are very mild. In the early stages, patients may find one or several white patches under their nails, sometimes in the center of the nail and sometimes at the nail root. If the patient is not treated, these spots can slowly expand to the periphery, and the patient may notice that the spots slowly become grayish-yellow and have visible flakes around them. The surface of the nail may also lose its luster and become uneven. As the condition of gray nails worsens, the patient’s nails may break down further and even fall off.