Q:

What causes black lines in fingernails?

A:

When black lines occur vertically in the nail, they are called longitudinal melanonychia, which is a condition caused by an overproduction of melanin. Similar to moles found on the skin, these lines are no cause for concern. This condition is more common among people who have dark skin.

Know More

Full Answer

Rarely, black lines may be caused by a subungual melanoma or cancer. For this reason, it's very important to have any suspicious lines looked at by a medical professional, especially if there is a family history of melanoma. Lines that change or spread into the cuticle or nail fold should also be treated with suspicion.

Learn more in Nail Care

Related Questions

  • Q:

    Why are my fingernails turning black?

    A:

    Black fingernails may be the result of a hematoma, according to Dr. Melissa Conrad Stöppler writing on MedicineNet. A hematoma is a pool of blood under fingernails that is usually the result of some type of trauma.

    Full Answer >
    Filed Under:
  • Q:

    What causes ridges in fingernails?

    A:

    According to Mayo Clinic, vertical ridges in fingernails are normal and have no specific cause; however, deeper ridges may occur as someone ages, possibly due to cell turnover. About.com says that less moisture from natural oils may also lead to more prominent ridges as someone ages.

    Full Answer >
    Filed Under:
  • Q:

    What causes fingernails to grow down?

    A:

    Fingernails can grow downward as a result of a condition called nail clubbing in which the fingers grow larger, while the nails grow around and curve over the larger fingertips, explains Mayo Clinic. Health problems such as low blood oxygen, inflammatory bowel disease, AIDS and cardiovascular disease can cause clubbing.

    Full Answer >
    Filed Under:
  • Q:

    What causes fingernails to curve down?

    A:

    Nails that curve downward, a condition known as nail clubbing, indicate that there could be an underlying health condition. Most often, these issues involve diseases of the lung and cardiovascular system. Nail clubbing may also indicate that the level of oxygen in the blood is low, according to Mayo Clinic.

    Full Answer >
    Filed Under:

Explore