Fungal Nail Infection

Also known as: Nail Fungus, Toenail Fungus, Fungal Toenails, Thickened Fungal Nails, Nail Fungal Disease, Yellow Fungal Nails

Last Updated: October 31, 2026

Key Points

Nails become brittle, discolored, or thicker
Commonly affects toenails, sometimes fingernails
Not serious but requires long-term treatment
Treatment options include topical medicines or oral tablets

Overview

A fungal nail infection, also known as onychomycosis, occurs when fungi infect one or more of your nails. This condition typically causes the nail to become brittle, discolored, or thicker than usual. While generally not serious, these infections can be persistent and take a long time to clear up. These infections most often affect toenails, though fingernails can also be involved. Fungi thrive in warm, damp environments, making feet particularly susceptible, especially when enclosed in shoes for extended periods. Early detection and consistent treatment are key to managing the infection and preventing its spread. Treatment can range from over-the-counter antifungal nail medicines to prescription oral tablets, depending on the severity and spread of the infection. In some severe cases, nail removal may be considered. Prevention focuses on good foot hygiene and avoiding conditions that encourage fungal growth.

Signs and Symptoms

Brittle nails
Discolored nails (yellow, brown, white)
Nails thicker than usual
Nail crumbling at the edge
Pain or discomfort (in severe cases)

Things That Increase the Risk

Warm and damp feet
Wearing trainers for long periods
Having hot, sweaty feet
Untreated athlete's foot
Diabetes
Weakened immune system (e.g., organ transplant, chemotherapy)

Diagnosis

Visual examination by a healthcare professional
Nail sample test to identify the type of fungus
Blood test to check liver function (if oral medication is considered)

Treatment & Management

Antifungal nail medicine (topical, brushed on)
Antifungal tablets (oral medication prescribed by a doctor)
Surgical removal of badly infected nails
Treating athlete's foot to prevent spread

Prevention

Treat athlete's foot promptly
Keep nails short and clean
Keep feet clean and dry
Wear clean socks daily
Wear flip-flops in public showers or pools
Wear well-fitting shoes
Avoid shoes that make feet hot and sweaty
Do not share towels or nail clippers

Available Treatments

Explore our range of treatment options for Fungal Nail Infection: