Fungal nail infections can cause a variety of changes in the affected nail, including:
• white or yellow spots or streaks under the nail
• nail thickening and roughness
• brittle, crumbling nail edges
• nail discoloration (white, yellow or brown)
• separation of the nail from the nail bed
Effective however can be toxic to liver and has other side effects. It is taken for 6-12 weeks and I would advise against taking it any longer. An example of oral antifungal is Lamisil and it does require prescription from your doctor.
Less effective due to reduced penetration into nail. Usually a paint or tincture applied to nail 1-7 days a week. Usually suggest for 3 months but really should be used for up to 12 months. Still has poor results and can work out very expensive. There are medicated treatments such as Loceryl, Canestan or Daktarin. There is also natural options such as Tea Tree Oil.
Laser is the upcoming treatment option however it is expensive and can be painful. Results still vary.