What do ridges on the fingernails indicate?

Vertical nail ridges, which run from the cuticle to the tip of the nail, are fairly common. They don't indicate serious illness and typically increase with age.

White lines and horizontal ridges,  although in exceedingly rare cases can be due to arsenic poisoning, are almost certainly normal. The nails grow from the nail bed and in most people the growth across the nail bed is a little up and down, which results in a corrugated appearance. It's quite normal and not a sign of any disease process.

http://www.netdoctor.co.uk/ate/skinandhair/205541.html

Nail ridges are fairly common in older people (I hope you're not offended if you happen to be young!). There is actually a medical term, "onychorrhexis," for this condition. Splitting occurs because of dryness, which causes the nails to get hard and brittle, leading to splitting near the nail tips. This can occur spontaneously or with minor trauma. Wrapping of nails or artificial tips may actually make the problem worse by not letting the nails "breathe". Does stress make them worse? Who knows! Stress probably is related to many conditions.

Dermatologists recommend using a strong moisturizer that contains lactic acid (like Eucerin cream) twice a day, especially after a shower or when the nails are wet. It may take several weeks before you see results. If the splitting persists, you should see a dermatologist to investigate the possibility of infection.

http://healthlink.mcw.edu/article/901226269.html

Vertical nail ridges, which run from the cuticle to the tip of the nail, somtime indicates a lack of Calcium and or Zinc(Spelter) in body. Somtime Liable to cause Like Fibrotic coating or overlay on the nail surface. It's also known consequence of bitted down nails at young age.

Recommended to try Zinc as Food supplement.

The vertical ridges can indicate a b12 anemia, get your B12 levels checked and be aware that if you are taking iron supplements this can mask this anemia.

Cheers ozmum.

I have ridges and always assumed that i have damaged the nail bed by hitting my fingers with a hammer whilst at work, both thumbs are ridged and thats the didgit that always gets wacked.

I dont know I am asking you

I think its lack of calcium.

i have always been told it is about your health. nothing to be to concerned about. perhaps start taking a multi vitamin.

Hope this will be of some help, and not get you paniced or excited. I never have bitten my nails, I am 51 years young, I occasionally use nail polish, have used acetone and non-acetone nailpolish remover, I am female, O+ Blood type, slim build since I was 12, and I started  noticing ridges on my nails (even toe nails) about 7 years ago. I have seen Doctors for my spine, had my gal bladder removed about 5 years ago, and still had the same pain in my back, and my fingernails got worse. Recently I had rib pain, odd for me, so the Dr. did a CT scan, compared it to the scan from 5 years ago when I had my Galbladder removed, and detected Lymphoma Cancer. I had previously been told by a Dr. the ridges might be a side effect from Reynaulds Syndrome (Burgers syndrome in men) because my knuckles were reddish compared to the rest of my hands as well, a sign of Reynaulds, but come to find out I am stage 4 with cancer in my lymphatic system AND it is in my Bone Marrow. I am apt to think the ridges may be an early indication of possible bone marrow/Lymphoma. Get to your Doctor and demand a CT scan, or a PET  scan. It is better to be safe than sorry. My prognosis is not good since I have B Cell (sub category) Mantle cell cancer. Please don't just depend on answers from laymen, or from others, seek a medical opinion from a real Doctor (I didn't until it was too late). Also, symptoms of lymphoma include mild night sweats to drenching night sweats (I had mild sweating on my forehead on  occasion, nothing to alarm anyone) and mild itching of the skin (like you feel a hair tickeling and brush your arm off scratch your head thinking it must be time to shampoo, feel like something is on your face so you swipe your hand across that, maybe feeling like a small sting on your  calf, so you run your hand across it... etc. Nothing major) and that is it... Not much of a symptom list for something so frightening and so deadly. Don't take any chances. Have a CT scan done, and in 6 months or  a year, have another and have them compared. Better to be safe than sorry. I hope this helps.