Nail Lines: Traces That Record the Body’s Past

Farzollah Gholizadeh and Fariba Bayrami

Nails grow slowly. This makes them interesting: they can carry on them the trace of some things the body went through weeks or even months ago.

Nail lines are one of these traces.

Lengthwise lines: usually normal

Fine lengthwise lines running from the base of the nail to its tip are very common, especially with age, and are usually normal.

Just as lines form in the skin over time, changes like these can appear in the nail.

But if lengthwise lines come with marked brittleness, dryness or a change in shape, the rest of the picture should be looked at too.

Crosswise lines: the body’s “notebook”

Sometimes clear crosswise lines at the same level on several nails (horizontal grooves) appear.

Lines like these can show that the nail’s normal growth was disrupted for a time. This disruption can follow:

• A serious illness
• A high fever
• Marked physical stress
• Some other demanding conditions

The line’s position can show the timing

The most interesting part is this: because the nail grows slowly and at a certain rate, the line’s position on the nail can give a specialist a clue as to roughly when the disruption happened.

If the line is near the base of the nail, the event was recent; if it is near the tip, it happened longer ago.

That’s why we sometimes call the nail a notebook that records the body’s past.

One nail, or all of them?

• If there is a line on just one nail, a knock or a local cause specific to that nail is more likely.
• If there are lines at the same level on several nails, an event affecting the body’s general condition is more likely.

This rule is not absolute, but it is the first step in observing correctly.

The traditional-medicine view

In Sina–Unani medicine, the nail is one of the tools for reading the body, together with the skin, hair, tongue and pulse. The quality of the nail can reflect how well the tissue is nourished and the body’s moisture–dryness balance.

But the basic principle of traditional medicine applies here too: the nail is read with the body, not apart from it.

When should you see a doctor?

• If the lines are new and there is no event to explain them
• If there are clear crosswise lines on several nails and the cause is unknown
• If the line comes with a change in colour, thickening or the nail separating from its bed
• If there is a dark (brown–black) line (this needs to be assessed separately)

Frequently asked questions

Are vertical lines on the nails a disease? Usually not; they are common with age.

Do crosswise lines go away? Yes. If the cause has gone, the line moves up as the nail grows and disappears when cut.

Do the lines show a vitamin deficiency? Not on their own. Nutrition can sometimes play a part, but a particular deficiency cannot be diagnosed by looking at the line.

Conclusion

Nail lines are usually harmless, but sometimes they silently record a hardship the body went through in the past. To read them correctly, look at the line’s direction, its position, how many nails have it and the accompanying signs.

For the nails’ other signs, read What Do Your Nails Say About Your Health?.

If you want to learn the body’s sign language step by step, Dr Kalan’s “Elaim & Delail” book and the Body Signs online course (currently in Turkish) will guide you. To start with your own baseline, take the free temperament test.