Sounds like a nail fungus. I have one too, on my big toe. I'm hoping cleansing will help get rid of the fungus by flushing out the toxins it may be feeding on. I asked a question in the home cures forum, someone suggested using vinegar on the nail. You can read all the suggestions in that forum.

as far as I understand, the yellow toenail is usually due to an overgrowth of microforms like candida or other yeast. I found some really good information on balancing the body to prevent and reverse such problems in a book by Dr. Robert O. Young, called the pH miracle. There is also a site for his supliments, I mostly recomend the pH drops and super greens, just cause they are what I have tried so far and had great success with (more energy, especially in the morning, wake up after 7 hours sleep with out alarm, eczema fading fast, and less recovery after exercise). But that's just my experience, check it out for yourself. The web site I recomend for the product is http://innerlightinc.iact1.com/mikelarsen . Or you can contact me directly, and I can help you out. Good health to everyone, Mike