
Nail ridges can appear for many different reasons, ranging from skin conditions to nutritional deficiencies. We’ll explain everything you need to know about this issue. Nail health is not only about appearance; it is also closely connected to overall wellbeing, since changes in the nails can sometimes reflect underlying health conditions.
One of the most common and visible changes is the appearance of ridges on the nails. While often harmless, these grooves can sometimes indicate systemic illnesses or nutrient deficiencies, among other causes.
According to a study published in the Indian Dermatology Online Journal, fingernail ridges tend to provide more reliable clues than toenail ridges. Learn why these lines form and what can be done about them.
What causes lines on the nails? Nail lines can develop for several reasons, including skin conditions such as eczema or atopic dermatitis, as well as deficiencies in protein, calcium, zinc, and vitamin A. The direction and depth of the lines play an important role in identifying their cause.

Vertical Lines
Vertical ridges run from the cuticle toward the tip of the nail. In general, older adults are more likely to develop mild vertical lines due to a natural slowdown in cell renewal. This happens when new cells form beneath the skin and gradually replace older, dead cells on the surface.
However, when additional symptoms appear—such as changes in color or texture—an underlying condition may be involved. For instance, in trachyonychia, which can occur alone or alongside other skin disorders, the nail surface may become rough, brittle, and discolored.
Similarly, individuals with iron-deficiency anemia may also develop vertical ridges. In some cases, changes in nail shape may cause a spoon-like or concave appearance.
Horizontal Lines
Horizontal ridges, also known as Beau’s lines, are often associated with more serious health conditions. These indentations can temporarily interrupt nail growth until the underlying issue is identified and treated.
Beau’s lines may indicate acute kidney disease, and when present across all 20 nails, they can be linked to conditions such as mumps, thyroid disorders, diabetes, or syphilis. According to a study published in Acta Haematologica, they may also appear in patients undergoing chemotherapy.

In addition, injury or trauma can lead to red or brown discoloration beneath the nails. It is important not to confuse these color changes with signs of serious diseases such as endocarditis or melanoma, where dark brown, black, or red pigmentation may appear.
How can you determine what’s causing the lines on your nails?
