Why would toe nails be yellewish brown and course?

Nail fungus: Nail fungus (caused by dermatophytes) is a very common problem and difficult to treat. Over the counter meds may help but a cure may be elusive. 2 different oral medications prescibed by a physician are available : Lamisil (terbinafine) (or generic) or sporonox. The cure rate with the 'pills' is only 70% , however. The duration of treatment is 3 months and the liver has to be 'checked' with blood tests.

Fungus: It sounds as if you have developed a nail fungus.

Possible fungus: Injured nail, stains from nail polish, smoking or lung disorders are some causes.