What does it mean when there are horizontal lines on fingernails?

Generally, horizontal ridges on fingernails may result from physiological factors or pathological conditions such as nail dystrophy or onychomycosis. The details are as follows:

1. Physiological Factors

With aging and skin senescence, nails gradually deteriorate, manifesting as an uneven nail surface with horizontal ridges. This is considered a normal physiological phenomenon.

2. Pathological Causes

1) Nail Dystrophy

The causes of nail dystrophy are complex and may be related to trauma or nutritional deficiencies due to picky eating, such as deficiencies in calcium, zinc, iron, or vitamins from group A or B. These deficiencies can lead to dysfunction of matrix cells in the nail, resulting in horizontal ridges.

2) Onychomycosis

This is a type of skin disease caused by fungal infection of the nail plate. It manifests as horizontal ridges on the fingernails, accompanied by clinical signs such as roughness, thickening, and brittleness of the nails, along with changes in nail color.

Besides the above, horizontal ridges may also be caused by paronychia. If horizontal ridges appear on the fingernails without systemic symptoms or other skin abnormalities on the hands, it is generally considered a normal occurrence and usually does not require treatment. However, if other discomforts or nail-related diseases are present, it is important to seek timely evaluation at the dermatology department of a reputable hospital. A dermatologist will perform a thorough examination and appropriate auxiliary tests to determine the underlying cause.