First of all, vertical nail ridges are fairly common and usually provide nothing to worry about. Vertical nail ridges often become more numerous or prominent with age. Now, if your fingernails change color or you develop horizontal nail ridges, you should consult your doctor. These changes could indicate an actual underlying health condition.
Second, and the point of my post today, don't be alarmed about every medical or pseudo-medical opinion you read on the internet. Further discussion with this patient in my office revealed that the site she read of progressive health deterioration that will occur following the discovery of vertical fingernail ridges, conveniently provided the solution to this problem. Their answer was by offering a rather expensive 'natural' bottled cure available for purchase at the end of the article.
Before you rush to the quick and easy answer to a promoted health issue read on the internet, further research the issue using reliable sources. Better yet, if it is a serious concern for you, speak with your doctor. Don't be embarrassed to bring a topic up. If you are afraid to ask a more reliable source, you may be left with erroneous information, potential harmful information or at least a lighter wallet.