Most people know about fungal nail infections, those slow infections that turn the nail black and cause it to crumble, but the idea of a yeast nail infection is less familiar. Scientifically, the yeasts do belong with the fungi, but in general they grow more quickly, they don't have the fluffy dusty appearance of molds, and they don't have a moldy odor. Colonies of yeast are typically rather smooth and creamy - these organisms cause vaginal yeast infections and thrush in the mouth, but they are also used for making bread and beer.

Many species of yeast can cause a nail infection. Typically, it is actually an infection of the skin under or around the nail called a paronychia. The yeasts like to grow where it is warm and moist, so the nail bed under the nail or the creases around the edge of the nail are ideal places for them. In addition, people who get these infections typically have their hands in water a lot so there is frequent abundant water applied to the site. A yeast nail infection can come on rather slowly, or it can flare up suddenly.

Bacteria can cause paronychia as well as yeast and nail infections should be seen by a doctor to be sure that treatment is appropriate. In a typical case, the tissue around the nail is red, swollen and tender, and there may be pockets of pus or pussy drainage. The infection can quickly spread to other fingers and toes. In a chronic yeast nail infection, that is, one that has come on slowly over days or weeks, the nail may be discolored, soft, and distorted.

Yeasts in general do not like an acid environment, so a good home remedy for yeast nail, infection is to soak the affected digits in a vinegar solution. This is thought to have some therapeutic value for paronychia caused by bacteria as well, and even for fungal nail infections - but again, if the infection has flared up suddenly, and particularly if it is uncomfortable, it should be seen by a doctor. If there is fever, pain in the arm or leg, or swollen lymph nodes, there should be no delay in seeking medical treatment - serious systemic infections are caused by bacteria and yeast and nail infections can be the source of organisms traveling to other parts of the body.

A nail infection that has developed over months without noticeable inflammation, turning the nail brownish or black and making it look distorted and flaky is probably a fungal nail infection rather than a yeast nail infection. In questionable cases, a doctor can take samples for laboratory testing to aid in diagnosis.