Med from doctor. Now thankfully the medications needed to treat fungus of the nails is generic and not so expensive. Nothing else works nearly as reliably. It can rarely cause liver problems to take these medications, but most people can take it safely.
Non- rx options. Soaks in vinegar or domeboro soaks can be helpful. Anti-fungal creams, like clotrimazole, miconazole, terbinafine, and others. Keep fingernails trimmed as short as possible. Avoid use of artificial nails. There are also prescription topicals and anti-fungal pills, if they won't clear up.
Topical, oral, laser. There are topical and oral antifungal medications available for the treatment of nail fungus. Specialized lasers are also now available for treatment of fungal nail infections. Have your nails evaluated and get the appropriate treatment.