Onychomycosis or Fungal Nail Infection is very common in toenails as fungal organisms are attracted to dark and humid environments such as inside a shoe. Fungal Nail Infection can affect any nail and any portion of nail. Cases can range from mild to severe. Nails with mild fungal infection appear white yellow in patches. the more severe fungal nails appear yellow, thick, crumbly and sometime painful. Most clients presenting with fungal nails report their main concern is the unsightly appearance of the fungal nails.