What causes yellowing, thickening, and hardening of toenails, and what should be done about it?
Nov 28, 2025
Source: Cainiu Health
Dr. Li Feng
Introduction
In general, yellowing, thickening, and hardening of toenails may be caused by aging, tight footwear or socks, onychomycosis (fungal nail infection), nail dystrophy, or nail damage due to psoriasis. If discomfort occurs, it is recommended to seek timely medical evaluation and treatment at a reputable hospital. In daily life, maintain clean and dry feet, avoid sharing shoes or socks with others, eat a balanced diet, and ensure adequate nutrition.
Generally, yellowing, thickening, and hardening of toenails may be caused by aging, tight footwear, onychomycosis, nail dystrophy, psoriatic nail damage, or other reasons. If discomfort occurs, it is recommended to seek timely medical evaluation and treatment at a reputable hospital. Specific causes are analyzed as follows:
1. Aging
With increasing age, nail plate metabolism slows down, leading to keratin accumulation that thickens the nails. Reduced sebum secretion causes nails to lose luster and turn yellow. Choose loose, breathable shoes and socks, soak feet in warm water for 10 minutes daily, and gently wipe the nails with a soft towel.
2. Shoe and Sock Pressure
Wearing narrow shoes and socks over a long period continuously compresses the toes, impairing blood circulation in the nail plates and causing abnormal keratinocyte hyperplasia, resulting in thickened and yellowed nails. Switch to loose-fitting, comfortable cotton socks and breathable footwear, and avoid prolonged walking or standing.
3. Onychomycosis (Fungal Nail Infection)
Fungal invasion of the nail plate by dermatophytes damages its structure, causing discoloration, thickening, and hardening of the nail, often accompanied by brittleness and increased debris. Medications such as terbinafine hydrochloride tablets, itraconazole capsules, and fluconazole tablets may be used under medical guidance, along with topical application of bifonazole cream.
4. Nail Dystrophy
Deficiency in nutrients such as vitamin A and calcium leads to inadequate nourishment for nail growth, resulting in yellowing, thickening, and brittleness. Under medical advice, supplements like vitamin A softgels, calcium gluconate tablets, and B-complex vitamins can be taken. Include more carrots and milk in the diet.
5. Psoriatic Nail Damage
Psoriasis affecting the nail matrix disrupts nail formation, leading to pitting, yellowing, and thickening of the nails, often accompanied by skin redness and scaling. Treatment under a physician’s guidance may include acitretin capsules, methotrexate tablets, or cyclosporine softgels. In severe cases, nail bed reconstruction surgery may be considered.
In daily life, maintain clean and dry feet, and avoid sharing shoes or socks with others; eat a balanced diet to ensure adequate nutrition; trim nails regularly without cutting them too short or too deep; seek prompt medical attention for any nail abnormalities to prevent delayed treatment.
