Onychomycosis (fungal infection)

Sign: This common infection can affect the finger and toe nails. Depending on the type of fungus, your nail may turn yellow, gray, brown or black. Often, the nail becomes thick and brittle, and cracks or separates from its bed. Your surrounding skin may become red, itchy or swollen. As the fungus grows, foul-smelling, moist debris can be seen. Pressure from a thickened nail or the build up of debris may make the toe painful.

Cause: It can develop on your nail or its outer edge, when your nails are continually exposed to a warm, moist environment or chemical.

Treatment: Although common, it's one of the most difficult infections to treat. Once an infection occurs, it can persist indefinitely if not treated. Refer to a dermatologist, as treatment is best begun at the early stages of infection. The accumulation of debris under the nail plate may lead to an ingrown nail, or to a more serious bacterial infection that can spread beyond the foot.

Discoloured Nails
This is a condition in which the nails turn a variety including yellow, blue, blue-gray, green, red and purple. Discoloration can be caused by poor circulation, a heart condition, or topical or oral medications. It may also indicate the presence of a systemic disorder. Artificial wraps, tips or an application of coloured polish can hide this condition.