Nails. They’re a handy surface to decorate; they help us pick up objects, scratch an itch and protect our fingers and toes.
But did you also know that nails can tell us a lot about your health and your well-being?
For most of us, fingernails are completely renewed in about six months.
That means that our nails are a six-month medical record incomparable to any physical exam component. A window into our metabolic soul…
Take a second and check them out now.
What do you see? Are they smooth, without pits or grooves? Are they uniform in color, strong, and free of spots and discoloration?
In my practice, I check everyone’s nails — preferably unpolished! And when I see something interesting and useful, I’ll file the pictures and track changes over time. Watching the changes of nails can let us know we’re on track with treatment. In this blog I want to share with you a few interesting cases, hopefully inspiring you to take a look at your own nails and to add this easy and useful investigation to the routine physical examination of your patients.
Anatomy of a nail
Image from Freethought Forum.
Nails are comprised primarily of the sulfur-rich protein, keratin, derived from tightly packed keratinocytes, the main cell type of the epithelium. Keratin is a highly biosorbent compound — it readily binds many essential and toxic metals and other chemicals. (UB biochemistry students: see the keratin protein structure below.) In fact, while writing this blog, I stumbled upon a rather nifty green chemistry paper looking at the feasibility of using modified keratin-rich chicken feathers for cleaning toxic waters. Great idea!
The human nail is thought to reflect total body status of many nutrients. Toxic, or imbalanced, levels of certain compounds can displace the normal distribution of nutrients in the nails, as well. We would expect, therefore, that such changes might be reflected visually.
“The nail growth, color, structure, and composition can vary by influence of several factors as nutritional and toxicological aspects, diseases and infections, gender, and age. All these indications make the human nail a potential source of information of the body status.”
“Virtually every nutritional deficiency can affect the growth of the nail in some manner.”
Further, we would also expect that nutrient-influenced nail changes to be relatively common, given the widespread evidence of nutrient insufficiencies and toxin presence.
Amazingly — but not surprisingly — doctors were keenly aware of the utility of the nail physical exam prior to the introduction of routine laboratory analysis. Indeed, some of our richer resources come from publications released in the early 20th century.
Biochemistry students: Look at the alpha helix and beta pleated sheets of keratin. The sheets are held together by hydrogen bonding. Cysteine (actually, cystine) is abundant in keratin, comprising up to 24% of total amino acid content. Therefore, many disulfide bridges are present in keratin, making it very ridged and stable.
This is the image of the thumb nail of a 60-year old woman presenting with inflammatory arthritis. The nail is slightly yellow, and prominent vertical ridging (onychorhexis) and white bands (leukonychia striata) are noted.
Onychorrhexis can be a normal variant — many of us have subtle ridging. However, when we see it more pronounced, especially when accompanied with brittle features, we can consider nutrient deficiencies, including protein and minerals. The leukonychia may point to specific deficiencies in selenium or zinc. Finally, the yellow color change (after ruling out smoking or recent nail polish) can be seen in autoimmunity, including rheumatoid arthritis; pulmonary disease and infection. Vitamin E may help to reverse yellowing.
A 16-year old girl presented with koilonycha, a spooning of the nails. This condition is commonly associated with iron deficiency, but zinc deficiency may also cause it. Her labs revealed very low zinc status, followed by a low-normal ferritin (iron status), but no anemia. Seshadri (see link below) mentions scurvy (vitamin C deficiency), pellagra (niacin deficiency), and riboflavin deficiency, as other possible causes of koilonychia. Protein malnutrition may also contribute.
A 63-year old woman presented with severe hand eczema with trachyonychia (20-nail dystrophy). Trachyonychia is a fairly common finding in those with hand eczema, ichthyosis vulgaris and alopecia areata. It’s also quite challenging to reverse. Her nutrient deficiencies included minerals zinc, selenium, copper and manganese; vitamins B12, folate and D.
After much work “inside-out” (improving diet and nutrient status), as well as “outside-in” (building her epidermal barrier), her hand eczema improved. Some months later, her nails grew back normally. The barrier work using fatty acids, occlusive and humectant topicals, as well as bleach baths, were essential to success. Needless to say, she was thrilled with the change, and relieved to be off the steroid merry-go-round.
Hand eczema in my experience isn’t so responsive to the “inside-out” approach that can work miracles with an atopic dermatitis that spares the hands. Hand eczema is often associated with a mutation in the epidermal barrier protein filaggrin.
Another pearl I’d like to mention is the relationship between osteopenia/osteoporosis and nail changes. If you observe brittle nails in a post-menopausal woman or an older man, check bone density. And, as bone density improves, observe the nails get stronger, too.
A few notes on well-being and nails: A cursory glance at your patient’s nails may reveal onychotillomania (nail picking) or onychophagia (nail biting). Such findings can be good openers for a chat about stress and anxiety. Improved well-being often correlates with favorable nail changes.
I encourage you to continue your exploration into nails and nutrients. Here’s a nice table with a link to the full text paper below.
From: Seshadri D, De D. Nails in nutritional deficiencies. Indian J Dermatol Venereol Leprol [2012;78:237-41
I live in Monmouth County, NJ, and looking for an ND. Any suggestions?
Cheryl, Try looking at http://www.functionalmedicine.org for a local doc trained in Functional Medicine. We offer telemedicine at my clinic as well. Good luck! DrKF
I’ve always found the health of my fingernails very important but haven’t been able to find articles like yours that go into detail. Because I’m not good with scientific names would you suggest any particular websites that can help me self diagnosis my problems with my nails.
Sometimes they don’t grow, sometimes they’re too bendable, sometimes that snap and break, sometimes the side edges start to need filing as they catch on things. So any advise so I can target my nutrition would be wonderful
Sharon, we do need to write a plain language blog on the topic! Thanks for pointing that out. For you- I’d think about digestive health, minerals and sufficient protein. If possible, check in with a local functional doctor for some ideas. Or you can consult with our AMAZING nutrition team if you’d like support. Reach us at firstname.lastname@example.org
Great info, but it would help if the “nail anomaly” list was a list of everyday lingo descriptions rather than names of anomalies since most of us have no idea what the current items listed are. I’m too lazy at the moment to Google each one, but may do later. “)
Good point. This piece is directed towards professionals, but we can certainly create a plain language version. DrKF
Great information! I would love to know what it means when the nail starts growing in a fan shape? (straight and then widening at the end)
I’m not sure without a pix. But could be koilonychia, which is caused by low iron and/or zinc–I’ve seen this condition sometimed present with a wider nail plate at the tip (distal end)….could look like a fan….Try the drop test: If there a scoop in the center of any of your nails that would allow a drop of water to be retained rather than roll off, could be the cause for you. I’d suggest getting tested for iron and zinc. But if you’re polishing your nails a lot, the fan look might be damage. DrKF
Hello, I recently went to my dermatologist because I have white type clouds that have grooves on my toe nails. I was diagnosed this year with Sjogrens Syndrome. I live in Monmouth County, New Jersey, near Freehold, and know one seems to know what it is called and what I need to take to correct the problem. Presently it is only on my largest Toe Nails. I have had Thrush also this year twice after being sick and on an antibiotic. I also have a white cloudy tongue and on one side it is disformed with points like the fissured photo of a tongue. Can you possibly help me determine what it is, and what to do for both these symptoms, it would be so appreciated. Thank you again.
Great job researching these symptoms and working on figuring out how to correct them. But sounds frustrating finding a practitioner to support you. It’s true that symptoms like those you described can be indicative of underlying imbalances or nutrient deficiencies. They’re certainly part of an extensive Functional Medicine evaluation – when considered as part of the full picture (along with autoimmunity) can lead to clues to help correct these imbalances. For Sjogren’s, in FxMed we’ve had some success approaching it with personalized autoimmune protocols, gut healing, and detoxification support. It would be ideal if you could find a Functional Medicine practitioner in NJ that you can work with to pull all those complex pieces together – I suggest starting with the IFM.org “Find a Practitioner” feature. Of course, you’re welcome to work with one of our Functional nutritionists remotely or visit our office in CT to work with one of our physicians.
Hi! Anything to be said for when fingernails look healthy but the toenails look bad (horizontal ridges/unevenness) in a toddler? Thank you!
Hi there. It all depends on the overall picture. Are there any other signs & symptoms of concern? How long have the nails been this way (ie is it a short-term, transient situation)? And how severe are the ridges? It is difficult to tell without the full picture, but if it is something that is of a concern you may wish to enlist the help of a functional medicine practitioner that can make the appropriate assessments and recommendations. We hope this post did not raise any alarms – our bodies are so complex and dynamic, thus there are many factors to consider before jumping to conclusions.