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Why do I have horizontal dents on my thumbnails?

2 doctors weighed in
Dr. Charles Li
Family Medicine
1 doctor agrees

In brief: Beau's Lines

You are describing beau's lines caused by a temporary cessation of cell division in the nail matrix.
Can be caused by an infection or problem in the nail fold, where the nail begins to form, or it may be caused by an injury to that area. Some other reasons for these lines include trauma, coronary occlusion, hypocalcaemia, and skin disease. Should see your doctor to investigate for these causes.

In brief: Beau's Lines

You are describing beau's lines caused by a temporary cessation of cell division in the nail matrix.
Can be caused by an infection or problem in the nail fold, where the nail begins to form, or it may be caused by an injury to that area. Some other reasons for these lines include trauma, coronary occlusion, hypocalcaemia, and skin disease. Should see your doctor to investigate for these causes.
Dr. Charles Li
Dr. Charles Li
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