The claim “If you have lines on your nails, it means you have cancer” is not true. Most nail lines are not caused by cancer.
The meaning depends on what kind of lines you have:
Vertical ridges (running from the cuticle to the tip)
- These are very common, especially as people get older.
- They are usually a normal part of aging and are not a sign of cancer.
Horizontal grooves (Beau’s lines)
- These can appear after a serious illness, surgery, high fever, or significant physical stress.
- They may also be associated with nutritional deficiencies or certain medical conditions.
Dark brown or black streaks
- Most are harmless, especially in people with darker skin, where normal pigmentation can cause streaks.
- However, a new, widening, or irregular dark streak in a single nail should be evaluated because, in rare cases, it can be due to a type of skin cancer called melanoma under the nail.
White lines or spots
- Small white spots are usually caused by minor nail injuries, not a vitamin deficiency.
- White lines across several nails can sometimes be associated with certain illnesses and should be assessed if persistent.
