According to the American Academy of Dermatology, the most common cause of a toenail infection is a fungus and 12 percent of Americans are affected by it. Normally, there are a number of bacteria and fungi present on the body, but a fungus can multiply quickly and cause a toenail infection. Another name for toenail fungus is onychomycosis. The two main fungi that affect the skin are yeast, known as Candida, and dermatophytes. Both types can affect the nails, but dermatophytes are more commonly associated with the toenails.

Symptoms

The dangers of a toenail fungus include developing the normal symptoms. According to the National Library of Medicine, these symptoms include the toenail becoming brittle or crumbling. The shape of the nail can change, and debris can get caught under the nail. The nail can become discolored, and there can be a loosening of the nail to the point that it becomes detached. The nail can also thicken or lose its luster.

Complications

Permanent toenail damage is a complication of a toenail fungal infection. There can also be pain associated with the infection which can become serious and spread beyond the toe, especially if the immune system is depressed. This is especially true in people who have AIDS, leukemia or have had an organ transplant. People taking certain medications may also have a suppressed immune system.

People with Diabetes

People with diabetes are especially susceptible to complications from a toenail infection. Circulation to the feet can become impaired. The nerves that go to the feet can also be impaired. People with diabetes are also at greater risk of developing a bacterial skin infection that has the potential to be serious. This bacterial skin infection is called cellulitis.

Fungal Paronychia

The National Library of Medicine also lists fungal paronychia as a complication of fungal toenail infections. Paronychia can cause an area around the toenail to swell and redden. Complications of paronychia include the development of an abscess and the infection spreading to bones, tendons or the bloodstream.