Before the last few years, my nails were always flat and smooth. But, now, I have vertical (lengthwise with the finger) ridges, too. And, if I don't keep them trimmed, some of the nails will tend to fold and cause a white line perpendicular to the nail and it will eventually split along that crease.
Despite questioning numerous doctors and many nights searching the Googleverse, I've never found a singular answer. The more common answers, though, have been:
* Zinc deficiency
* Protein deficiency
* Malabsorption (this could affect the above two)
* Low stomach acid (this could affect the above three)
One Naturopath suggested I purchase the book Dr. Chi's Fingernail & Tongue Analysis Book
, but it was $60 and I had no way to know if it was legit or just more questionable "alternative" nostrums.
Luckily, though, my Google prowess paid-off somewhat and I found a 30-page PDF file of Dr. Chi's notes from a lecture titled The Role of Fingernail and Tongue Analysis and Herbal Practice
Some of Dr. Chi's answers to the cause of vertical ridges?
* Vitamin deficiency
* Peripheral blood vessel disease
I really should stay away from Googling health conditions and stick with cat videos on YouTube.
For what it's worth, a few years ago, I had a Heidelberg Gastric Analysis (where I swallowed a capsule that contained a pH meter and radio transmitter) and was alleged to have had low stomach acid.
A Genova "NutrEval Plasma" test reported I was "Borderline" low in all the B-vitamins and I had a "High Need" for Thiamine (Vitamin B1) in particular. Reportedly, I was also "Borderline" low for Manganese and Zinc and had a "High Need" for Magnesium. They suggested a daily Probiotic with 50 billion CFUs, eight Amino Acids, and Pancreatic Enzymes.
Finally, a "Toxic & Essential Elements Hair Analysis" from Doctor's Data also showed me to be low in elements like Calcium, Magnesium, Sodium, Potassium, Copper, Zinc, Manganese, Boron, Lithium, Strontium, Cobalt, Iron, Rubidium, and Zirconium.
If I were guessing (and, I am), I'd say it's a vitamin and/or mineral deficiency, due to hypochlorhydria and/or malabsorption.
But, who knows?
If you find anything conclusive, please let us know.