# What are those white marks on your fingernails? **URL:** \ **Category:** Factual Questions\ **Created:** [December 25, 2000, 4:48am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156 "2000-12-25T04:48:59Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![galyean](https://avatars.discourse-cdn.com/v4/letter/g/f9ae1b/32.png) [@galyean](https://boards.straightdope.com/u/galyean)\ **Post date:** [December 25, 2000, 4:48am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/1 "2000-12-25T04:48:59Z")
My fingernails sometimes have white marks/spots that eventually grow out with the nail and get clipped off. What are they? Are they mineral deposits or bruises that grew out from behind the cuticle? Are they something else entirely? I know this has likely been answered before, but I must be using the wrong search keywords because I couldn’t find it here. ---
**Author:** ![Conti](https://avatars.discourse-cdn.com/v4/letter/c/c67d28/32.png) [@Conti](https://boards.straightdope.com/u/Conti)\ **Post date:** [December 25, 2000, 4:54am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/2 "2000-12-25T04:54:48Z")
I believe they are pockets of air trapped under there. ---
**Author:** ![galyean](https://avatars.discourse-cdn.com/v4/letter/g/f9ae1b/32.png) [@galyean](https://boards.straightdope.com/u/galyean)\ **Post date:** [December 25, 2000, 4:58am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/3 "2000-12-25T04:58:26Z")
No, they can’t be pockets of air. When the marks reach the tips of my nails they don’t go away…if you mean trapped between the nail and the underlying skin. ---
**Author:** ![Conti](https://avatars.discourse-cdn.com/v4/letter/c/c67d28/32.png) [@Conti](https://boards.straightdope.com/u/Conti)\ **Post date:** [December 25, 2000, 5:15am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/4 "2000-12-25T05:15:25Z")
Cecil describes this in [http://www.straightdope.com/classics/a3\_035.html](http://www.straightdope.com/classics/a3_035.html) It might be something different than what you’re talking about, but i believe it is the right answer. ---
**Author:** ![Obvious\_Guy](https://avatars.discourse-cdn.com/v4/letter/o/e9c0ed/32.png) [@Obvious\_Guy](https://boards.straightdope.com/u/Obvious_Guy)\ **Post date:** [December 25, 2000, 5:19am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/5 "2000-12-25T05:19:07Z")
I have heard that they are stress marks. For instance people who have had heart attacks may alot of them. Thats not to say that heart attacks cause them but either mental or bodily stress. ---
**Author:** ![KCB615](https://avatars.discourse-cdn.com/v4/letter/k/ea666f/32.png) [@KCB615](https://boards.straightdope.com/u/KCB615)\ **Post date:** [December 25, 2000, 5:45am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/6 "2000-12-25T05:45:22Z")
I allways thought they were from trauma suffered by the the end of the finger, just below the nail. For instance, I have 2 good sized white marks on my left ring finger. About a month and a half ago, I slammed that finger in a door. Big time. Fingertip swelled up like nothing I’ve seen before. Hurt like a sonofagun, too. But, about 2 weeks after I slammed that finger, the white spot began to work its way up my nail. Seems that whenever I have some type of trauma to a nail area, the white spots appear a week or two later. Just my observation… ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [December 25, 2000, 11:44am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/7 "2000-12-25T11:44:54Z")
Speaking of fingernail features and anomalies, does anyone else have those longitudinal striations? Those thin ridges parallel to the direction of growth? Sometimes they are unbroken lines and sometimes they come in segments with rounded ends. Any idea what they signify, if anything? ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [December 25, 2000, 2:34pm UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/8 "2000-12-25T14:34:53Z")
> [@](#): > > \*Originally posted by ishmintingas \* > \*\*Speaking of fingernail features and anomalies, does anyone else have those longitudinal striations? Those thin ridges parallel to the direction of growth? Sometimes they are unbroken lines and sometimes they come in segments with rounded ends. Any idea what they signify, if anything? \*\* I have read and been told that this happens frequently to diabetics after several years. I know I have one on my thumbnail that appeared about 5 years ago. Actually, the best way to describe it is a longitudinal “weak valley” in the direction of growth. ---
**Author:** ![lolagranola](https://avatars.discourse-cdn.com/v4/letter/l/ea5d25/32.png) [@lolagranola](https://boards.straightdope.com/u/lolagranola)\ **Post date:** [December 25, 2000, 5:04pm UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/9 "2000-12-25T17:04:42Z")
But why does it happen to diabetics? I have had the same thing on my left thumbnail since my first pregnancy, 10 years ago. It’s really annoying, since it’s a weak spot in my nail. I like to grow my nails long, but I have a hard time growing that one thumbnail, because of the weak growth along that white line. ---
**Author:** ![Patty\_O\_Furniture](https://avatars.discourse-cdn.com/v4/letter/p/96bed5/32.png) [@Patty\_O\_Furniture](https://boards.straightdope.com/u/Patty_O_Furniture)\ **Post date:** [December 25, 2000, 6:37pm UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/10 "2000-12-25T18:37:51Z")
I have those marks on all ten (possibly twenty, but I’m not going to take my socks off at work. Shoes yes, but not socks.) of my nails. And I am not diabetic. ---
**Author:** ![mega\_the\_roo](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@mega\_the\_roo](https://boards.straightdope.com/u/mega_the_roo)\ **Post date:** [December 25, 2000, 8:22pm UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/11 "2000-12-25T20:22:18Z")
You can get them from banging your nail onto something. That’s usually what mine are from. ---
**Author:** ![Kilgore\_Trout\_1](https://avatars.discourse-cdn.com/v4/letter/k/6de8d8/32.png) [@Kilgore\_Trout\_1](https://boards.straightdope.com/u/Kilgore_Trout_1)\ **Post date:** [December 25, 2000, 8:35pm UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/12 "2000-12-25T20:35:05Z")
this is the very question that led me to the straight dope. ---
**Author:** ![lesa](https://avatars.discourse-cdn.com/v4/letter/l/34f0e0/32.png) [@lesa](https://boards.straightdope.com/u/lesa)\ **Post date:** [December 26, 2000, 12:50am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/13 "2000-12-26T00:50:29Z")
I used to have these all the time. I thought it was because I was accident prone and kept hitting my hands on things. But the spots cleared up when I started taking zinc (and magnesium). There’s a letter about this at the end of the column Conti provides a link to. I was never worried about these spots, I was taking magnesium and malic acid for my Chronic Fatigue Syndrome. The suplement also had zinc in it. I was very surprised when all the white spots went away. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [December 26, 2000, 2:43am UTC](https://boards.straightdope.com/t/what-are-those-white-marks-on-your-fingernails/47156/14 "2000-12-26T02:43:18Z")
Fingernails can reveal information about a person’s health. Some examples: 1. White nails (a.k.a. Terry’s Nails a.k.a. leukonychia) - low albumin (protein) seen in advanced liver disease and malnutrition. 2. Horizontal lines (Beau’s nails) - these intermittent bands correspond to major physical stress such as cycles of chemotherapy ([good picture of Beau’s nails](http://www.nejm.org/content/1995/0333/0002/0100.asp)). 3. Spoon nails (koilonychia) - a sign of iron deficiency (don’t ask me why). 4. Separation of the end of the nail from the nail bed (onycholysis) - seen in numerous serious medical conditions as well as fungus infections of the nails themselves. 5. Pitting of the nails - tiny punctate depressions in the nails; common in psoriasis. 6. Clubbing of the nails (actually clubbing of the finger and nails - the ends of the fingers (and toes) take on a dilated, club shape; seen in lung cancer, chronic lung infections, bowel diseases, congenital heart disease, … One site that has some pictures and seems reputable is [here](http://www.mayohealth.org/mayo/9702/htm/finger.htm#ww5rl80). Indeed, there seem to be zillions of sites around discussing nail abnormalities. I found a bunch simply by typing “leukonychia” into Yahoo. BTW, I don’t have a clue what causes those little white spots that the OP was inquiring about.