Most people don’t really pay attention to the little half-moon-shaped white portion at the base of their nails. We just accept that it’s there and move on with our lives.
However, believe it or not, that little white half-moon on your nail can tell you a lot more about yourself that we originally realized. For starters, it’s not just a white mark on your nail. The half-moon is actually an entirely separate piece of a person’s body.
The half-moon on your nail isn’t actually on your nail. It’s underneath the nail, attached to that skin the lies beneath the hard surface of the nail. It’s called a lunula.
Lunula quite fittingly means “little moon” in Latin. It acts as the protective covering for the blood vessels that lie underneath the skin. Without a lunula, those blood vessels would be very vulnerable.
While its function is to protect those otherwise vulnerable blood vessels, the lunula can actually warn a person about potential health concerns. It’s important to take note of each lunula and make sure none is atypical.
A study in the 1996 Journal of the Academy of Dermatology laid out guidelines for typical lunulae (plural for “lunula”). According to the study, a healthy lunula will be ivory in color, half-moon shaped, and take up about one-fifth of the entire nail.
If you notice any strange variation in the color, shape, or size of your lunulae, then you might consider consulting a doctor to make sure everything is fine with your health.
It’s important to remember that only a doctor can diagnose a health disorder and that just because a lunula looks different than these guidelines, it doesn’t necessarily mean something is certainly wrong. That said, there are a few warning signs to watch out for.
According to that 1996 study, your lunulae should be an ivory color. If your lunula is a red color, it might indicate alopecia, vitiligo, or psoriasis. If your lunula is a yellow color, then it might be indicating exposure to insecticides or pesticides.
Finally, blue-colored lunulae have been associated with Wilson’s disease and Hemoglobin M disease. It’s also a potential sign of systematic drug ingestion, such as with chemotherapy recipients.
Your lunulae might grow into a different shape if you have some other illness, such as Turner’s Syndrome, or a chromosomal disorder, such as Down Syndrome. An oddly-shaped lunula can also occur if you have experienced some sort of nail trauma.
It’s important to pay attention to the shape of your lunula because its shape can affect the way your nail grows.
As stated earlier, your lunula should take up about one-fifth of the entire nail. An enlarged lunula is called macrolunula. Macrolunula is normal for some ethnicities, such as people of Indian descent, but otherwise, it can indicate endocrine disorders, such as hyperthyroidism.
When the lunula is much smaller than normal, it is called microlunula. Microlunula is normal for some ethnicities, such as those of African descent. It’s also common with age.
However, microlunula can also signify certain health disorders, such as cardiovascular atherosclerosis (hardening and narrowing of the arteries), rheumatoid arthritis, and iron-deficiency anemia.
While variations in the lunula could be completely benign, it could be a good idea to call a doctor if you feel that any of these lunula abnormalities are occurring beneath your own nails.