Nail Health Science

Nail performance can be used as a reference for health status, but the one-to-one correspondences such as "less crescents = physical weakness" and "vertical lines = poor liver and kidneys" have no evidence-based medical basis. Diseases cannot be diagnosed solely by nail performance. If there are any abnormalities, you should first check for local problems or see a dermatologist. Don't blindly take supplements.

Damn, last week I was dragged by my best friend to look at her hands. After she had her manicure removed a while ago, she found that only her thumb had 2 crescents. She posted a short video saying that less than 6 crescents meant Qi and blood deficiency. I was about to stock up on donkey-hide gelatin oral liquid. I pulled her to remove the familiar skin. The dermatologist laughed at one glance and said that every time she did a manicure, she asked the manicurist to grind the nail surface very thin. The nail base was pushed back and the crescent moon naturally could not be exposed.

Speaking of which, crescent moons are the hardest hit area for rumors about nail health. It must be said objectively here that in traditional Chinese medicine syndrome differentiation, the size and number of crescent moons are indeed used as one of the reference items for the prosperity and decline of Qi and blood. However, this is a comprehensive judgment based on tongue coating, pulse condition, and overall condition. There has never been a saying that "less than a few crescent moons are diseased."； The view of modern dermatology is more straightforward. The essence of the lunula is the nail matrix that has not been completely keratinized. Some people are born with the nail matrix growing farther back, or their nails grow slowly. Only their thumbs have lunula throughout their lives, and they are completely healthy. What you really need to be wary of are "mutations in a short period of time" - for example, 10 fingers had crescents before, but suddenly 2 are left within a few months, or the crescents suddenly become larger and occupy one-third of the nail. The former may be related to hypothyroidism and malnutrition, while the latter requires checking for hyperthyroidism. Only such changes have clinical significance.

After talking about the crescent moon, let’s talk about the vertical lines that many people are worried about. I have a shallow vertical line on my right index finger. It has been with me for five or six years. The annual physical examination of liver and kidney function is normal. Last time I asked the doctor, people said that it is the same as wrinkles on your face. After the age of 25, the growth rate of nails slows down and the keratinization metabolism of the nail epithelium is not so uniform. It is normal to have shallow vertical lines. It is not a "bad liver and kidney detoxification" at all. Oh yes, here is an important point: if the vertical lines are deep black, more than 3mm wide, have blurred edges, and suddenly become wider in a short period of time, don’t hesitate to go to the dermatology department for a dermoscopy to check for onychomycosis or malignant melanoma. I saw a patient in the clinic last year. I thought it was just an ordinary black line at first, but it took two years to come and it has turned malignant. Don’t be careless about this.

There are also people who panic when small white spots appear on their nails, saying that it is due to calcium and zinc deficiency. When I was a child, my mother forced me to drink zinc gluconate for half a year. Later I found out that 90% of the white spots are caused by nail trauma. For example, if you pinched your finger while closing a door, knocked the tip of your nail while cleaning the table, or touched the nail base while doing a manicure, you may not feel it at the time. When the nail grows out, it will become a white spot. After two or three months, it will recede as the nail grows, and it will not affect anything. Unless the nails are white and do not fade when pressed, then anemia and fungal infection should be investigated.

Many girls ask me whether doing manicure will hurt the nails. In fact, there is no unified conclusion in the industry. Some people think that as long as you use qualified nail polish glue, do not damage the matrix of the nail when polishing, and do not pick hard when removing the nails, it is perfectly fine to do it occasionally.； There is also clinical data showing that people who have done manicures continuously for more than three months have about 40% higher rates of nail thinning, brittleness, and fungal infection than people who don’t do it. I also do manicures myself. I usually do it for a month and take a month off. I always go to a regular store to apply nail polish remover to remove my nails. I never pick them off. I treated a college student before and he did manicures for half a year without stopping. Later, his nails turned green all over, which was caused by Pseudomonas aeruginosa infection. It took almost 4 months for new and good nails to grow, so there is really no need to demonize manicures, but don’t stress too much.

There are also many people asking whether they should buy those armor-protecting vitamins that cost hundreds of dollars a bottle. To be honest, most people don’t need them. Unless you have been diagnosed with iron deficiency anemia, B vitamin deficiency or zinc deficiency - for example, people with iron deficiency may have spoon-shaped nails, which means that the edge of the nail is upward, like a small spoon. After iron supplementation, it will slowly recover. ； People who are deficient in B group may have their nails easily broken and delaminated, so it is also useful to make up for it appropriately. Normal people usually eat enough eggs, lean meats, green leafy vegetables, and nuts, and the nutrients are completely sufficient for their nails. If you chew your nails less, don't use your nails to open beer bottles, and don't pick your nails to open express delivery, it will be more effective than how many supplements you take.

In fact, you really don’t need to stare at your nails and think about them over and over again every day. It will make you more anxious if you follow the symptoms online. If your nails suddenly have strange changes - such as suddenly thickening and peeling, pain, strange black spots, or deformation of the entire nail, you can directly call a dermatologist for more than ten yuan, which is much more reliable than scaring yourself by watching short videos for half a day.