Lines on your nails usually do not mean you have cancer.
Different kinds of nail lines can happen for many reasons:
- Vertical ridges (running from cuticle to tip) are very common and often come with aging.
- Horizontal grooves (called Beau’s lines) can appear after illness, stress, injury, or nutritional problems.
- White lines or spots are often from minor trauma to the nail.
- A dark brown or black streak under one nail can rarely be a sign of Melanoma, especially if it’s new, widening, irregular, or extends onto the skin around the nail.
You should consider seeing a doctor or dermatologist if you notice:
- a new dark stripe,
- rapid nail changes,
- nail separation or bleeding,
- pain,
- or changes affecting only one nail without an obvious injury.
A social-media claim like “lines on your nails mean cancer” is overly broad and misleading. Most nail lines are harmless.
