Nail lines are very common, and in many cases they’re harmless. But sometimes, your nails can reflect changes happening inside your body.
1. Vertical Lines on Nails
These lines run from the base of the nail to the tip.
They are often linked to:
Aging
Dry nails
Minor vitamin deficiencies
Dehydration
They usually become more visible with age and are not dangerous in most cases.
2. Horizontal Lines (Beau’s Lines)
These lines go across the nail from side to side.
They may appear after:
Severe stress
High fever
Illness or infection
Poor nutrition
Injury to the nail
Sometimes they can signal that the body temporarily stopped normal nail growth.
3. White Lines or Spots
Many people think white spots mean calcium deficiency, but they are more commonly caused by:
Minor nail injuries
Allergic reactions
Nail product irritation
4. Dark Lines Under the Nail
Dark streaks should never be ignored, especially if they appear suddenly or grow wider.
Possible causes include:
Injury
Pigment changes
In rare cases, skin cancer
A doctor should examine persistent dark lines.
5. Ridged or Brittle Nails
Weak nails with deep ridges can sometimes be linked to:
Iron deficiency
Low vitamin B levels
Thyroid issues
Poor diet
When to See a Doctor
You should seek medical advice if:
The lines suddenly appear
Nails change color
Nails become painful or split
Only one nail is affected with a dark streak
Your nails can reveal clues about your health, but they cannot diagnose diseases on their own. A proper medical evaluation is always important.