If You Have These Lines on Your Nails After 40, It May Be a Sign of…
Lines on fingernails after age 40 are very common and often harmless. Many viral health posts claim that nail lines are a “clear sign” of a serious disease, but the truth is more nuanced: the type, pattern, and changes over time matter.
Common types of nail lines and what they may mean
1. Vertical ridges (lines running from the cuticle to the tip)
These are the most common.
They may be related to:
- Normal aging changes
- Drier nails as the body produces less natural oil
- Genetics
- Repeated exposure to water, soaps, or chemicals
Many healthy adults develop these ridges over time.
2. Horizontal grooves (lines across the nail)
These are called Beau’s lines. They can appear when nail growth temporarily slows.
Possible causes include:
- A recent illness or fever
- Significant physical stress
- Injury to the nail
- Certain medications
- Poorly controlled health conditions
3. White lines or spots
White marks are often caused by:
- Minor nail injuries
- Trauma to the nail base
- Normal nail changes
They are not automatically a sign of calcium deficiency.
4. Dark vertical lines
A brown or black stripe under a nail can sometimes be harmless, but a new, changing, widening, or irregular dark line should be checked by a healthcare professional because, in some cases, it can be associated with skin cancer under the nail (subungual melanoma
