The appearance of lines or ridges on fingernails may worry many, especially if they appear suddenly or were not present before. However, dermatologists confirm that most of these changes are normal and not dangerous, while some cases may indicate health problems that require medical evaluation.

Dr. Shari Lipner, professor of dermatology at Weill Cornell Medicine and NewYork-Presbyterian Hospital in the United States, explained that vertical lines extending from the base of the nail to its tip are often a normal part of the aging process and are the most common type of nail ridges, according to Prevention magazine.

In contrast, horizontal ridges, medically known as Beau's lines, differ from vertical ridges; they usually arise from a temporary halt in nail growth and may be linked to direct injury, severe illness, or other health factors.

American dermatologist Dr. Tsippora Shainhouse said that the appearance of horizontal ridges on a single nail is often due to injury to the nail growth area, such as slamming the finger in a door or repeated picking at the nails, resulting in a groove that gradually disappears as the nail grows.

For his part, American dermatologist Dr. Karan Lal explained that horizontal ridges may also appear when the body experiences severe stress leading to a temporary halt in nail growth. Prominent causes include severe viral infections, fever, kidney disease, deficiencies in certain nutrients such as iron, zinc, and vitamin A, as well as damage from artificial nails or direct injuries, psychological stress, and thyroid disorders.

He added that vertical ridges may also be associated with dry nails, certain skin conditions such as eczema and psoriasis, autoimmune diseases like alopecia areata, as well as aging, iron or zinc deficiency, vitamin A deficiency, and thyroid disorders.

Experts pointed out that white spots or lines are different from nail ridges and are medically known as leukonychia. They often result from minor injuries, such as nail biting or hitting a hard object, but may also be linked to certain skin diseases or medications.

How to Maintain Nail Health?

American dermatologist Dr. Donna Hart confirmed that regularly moisturizing nails with creams or oils containing ceramides or alpha hydroxy acids helps reduce the appearance of ridges and preserves the keratin inside the nail.

To maintain nail health, experts recommend trimming them regularly without cutting them excessively, refraining from biting them or picking at the surrounding skin, and using nail polish in moderation, as overuse may thin the nail and make it more prone to breakage.

They also advise against pushing back or removing the cuticle, as it forms a natural barrier that protects against infection, while limiting repeated exposure to water and wearing gloves when washing dishes or doing housework.

When to See a Doctor?

According to experts, a doctor should be consulted if nail ridges appear suddenly, are accompanied by pain or splitting of the nail, the nail color changes to brown or black, or there are clear changes in its surface.

Karan Lal explained that evaluating the condition begins with examining the skin and nails for signs of diseases such as psoriasis, and may require tests including a complete blood count (CBC), comprehensive metabolic panel (CMP), iron level measurement, and thyroid function tests to help identify the underlying cause of these changes.