HEALTH TOPICS 
By the way, doctor: What do these lines on my fingernails mean?
Q. Would you please tell me what it means when fingernails have vertical or horizontal lines?
A. Vertical lines or ridging is a natural part of nail growth. These lines may be more pronounced in some people's nails, particularly as they get older, but the ridges are usually mild. More severe, deep lines and splits may be seen with certain skin diseases, such as lichen planus.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
New subscriptions to Harvard Health Online are temporarily unavailable. Click the button below to learn about our other subscription offers.