City Footcare NYC

Podiatric Medicine & Surgery

We treat all problems of the foot and ankle.

Toenail Fungus


Toenail fungus, known by physicians as Onychomycosis, affects about half of Americans by the age of 70.

It is relatively rare in children, and the incidence increases with age.

Fungal infections occur when microscopic fungi gain entry through a small trauma in the nail, then grow and spread in the warm, moist environment inside the patient’s socks and shoes.

Symptoms of toenail fungus, which can be caused by several types of fungi, include swelling, yellowing, thickening or crumbling of the nail. There can also be streaks or spots down the side of the nail, and even complete loss of the nail. Toenail color can vary from brown or yellow to white with this condition.

Fungal infections can affect the fingernails as well as the toenails, but toenail fungus is more difficult to treat because toenails grow more slowly and are confined to dark, warm, moist environments.

Toenail fungus occurs most often on the big or small toe, due to their prominence and rubbing on shoes, but may occur on any toe.


Toenail fungus can be picked up in damp areas such as public gyms, shower stalls or swimming pools, and can be passed among family members.

Athletes and people who wear tight-fitting shoes or tight hosiery that cause trauma to the toes, or keep the feet from drying out, are at higher risk.

The condition can also spread from one toe to another, or to other parts of the body.

Other risk factors include abnormal PH level of the skin, not drying off the feet thoroughly after bathing or exercise, and a compromised immune system in someone who has been exposed to a fungus.

Diabetics have an increased risk of contracting a toenail fungus because their immune system can be compromised.