Both fingernails and toenails have vertical ridges.

Vertical ridges on both fingernails and toenails may be caused by factors such as deficiency of trace elements, chemical damage, or onychomycosis. Treatment should be selected based on the specific cause. Detailed analysis is as follows:

1. Deficiency of trace elements

When there is a lack of vitamins or trace elements—such as zinc or copper—fingernails and toenails may become uneven and develop vertical ridges. Under medical guidance, patients may take medications such as zinc gluconate oral solution or multivitamin tablets.

2. Chemical damage

In daily life, frequently applying nail polish to fingernails and toenails can cause nail damage and lead to the appearance of vertical ridges. To prevent this, avoid frequent nail beautification procedures. Regular use of cuticle oils with moisturizing and protective properties can help nourish the nails.

3. Onychomycosis

This is a fungal infection of the nail plate and underlying tissue caused by dermatophytes. When fungi invade the fingernails or toenails, they disrupt the normal nail structure and cause abnormal keratinocyte proliferation, resulting in vertical ridges. Under medical supervision, topical treatments such as miconazole nitrate cream or Shanhua Xuanjing (Coral Fungus Solution) may be used.

In addition to the common causes mentioned above, other conditions such as trauma, endocrine disorders, or lichen planus may also contribute. If any discomfort or symptoms occur, it is recommended to seek timely medical evaluation and treatment.