Yep...there is a fungus amungus. Not sure of the exact cause of this, but it is very common and not based on your hygiene. As the fungus is Under the nails, about the only way to get rid of it is taking pills everyday for a year. There are topical treatments that can help reduce the symptoms, but may not cure it.
Visit your local physician for more information.
......Plain ol' Laurie---NOT Dr. Laurie