What does it mean if there are black vertical lines on the nails?
Sep 13, 2024
Source: Cainiu Health
Dr. Yang Ziqi
Introduction
Black vertical lines on the nails may be caused by aging, external trauma, malnutrition, nail melanotic macules (melanonychia), or fungal infections. If the black streak is due to bruising from trauma, special treatment is usually unnecessary; as the nail grows, the blood clot will gradually grow out and disappear. However, if the discoloration persists for a long time or is accompanied by pain, procedures such as drainage via puncture may be performed under medical supervision.
Under normal circumstances, black vertical lines on the nails may be caused by aging, external trauma, malnutrition, nail matrix nevus (melanonychia), or fungal infection. If discomfort occurs, seek medical attention promptly. Detailed analysis is as follows:
1. Aging
With increasing age, pigment deposition in the nails may form fine vertical lines, among which black vertical lines occasionally appear. No specific treatment is required; maintain a healthy lifestyle, regularly trim nails, and keep them clean.
2. External Trauma
Physical force applied to the nail can stimulate local melanocytes to become active, leading to melanin deposition at the injured site and causing the aforementioned symptoms. Keep the injured area clean and avoid secondary injury. In most cases, as the nail grows, the black vertical line will gradually move outward and disappear.
3. Malnutrition
Factors such as dieting for weight loss or excessive fatigue may lead to malnutrition. Deficiency in vitamins or trace elements may cause brittle, fragile nails with black vertical lines, possibly accompanied by symptoms like hair loss and dry skin. Treatment should follow medical advice and may include medications such as ferrous sulfate tablets, zinc gluconate oral solution, and vitamin C effervescent tablets.
4. Nail Matrix Nevus (Melanonychia)
Hormonal imbalances, improper diet, and other factors may trigger a nail matrix nevus. This condition involves benign proliferation of melanocytes. When located at the base of the nail, the melanocytes deposit pigment into the nail plate as it grows, forming a black vertical line. If a nail matrix nevus is suspected, consult a dermatologist. Diagnosis is confirmed via biopsy, and if necessary, minimally invasive surgical excision is performed—this involves making a small incision near the nail to expose and promptly remove the affected tissue.
5. Fungal Infection
Poor lifestyle habits or exposure to certain external substances may lead to fungal infection. The infection damages the nail structure, disrupts microcirculation beneath the nail bed, and promotes melanin deposition, resulting in black vertical lines. Symptoms may include nail thickening or deformation. Treatment should follow medical guidance and may involve antifungal medications such as itraconazole capsules, terbinafine hydrochloride tablets, or clotrimazole cream.
Maintain clean and well-trimmed nails, and avoid letting nails grow too long to prevent breakage or infection.
