Identify different nail diseases by associating certain diseases or disorders with physical characteristics of those diseases that manifest in the nails, notes MedlinePlus. These characteristics not only denote nail disorders but other diseases throughout the body as well, explains WebMD.
Paronychia, a nail disease caused by a bacterial infection, causes the skin around the nails to become swollen and inflamed, according to MedlinePlus. Beau's lines is a disease that causes horizontal trenches in the nail as a result of another disease or as the body's response to chemotherapy. Nail discoloration, pitting and cracking characterize fungal nail infection or onychomycosis, often occurring in toenails as a result of athlete's foot. Nail lifting and nail splitting, onycholysis and onychoschizia respectively, occur because of skin conditions or other medical problems such as eczema, psoriasis, gland diseases and malnutrition.
Many nail diseases are a result of fungal infections such as distal subungual onychomycosis and candida onychomycosis, states WebMD. The former is the most common nail infection, while the latter is caused by a yeast infection, discoloring and even misshaping the nail. As the name suggests, white superficial onychomycosis manifests in white spots and a chalky powder on the nail. Proximal subungual onychomycosis is more rare, occurring in people with HIV and weakened immune systems. The base of the nail thickens and turns opaque.