This is a diabetic patient who hasn’t been in to see me for several years. Her nails have gotten quite thick and long.
Toenails can become thick for various reasons. They can thicken with age, from injury, due to poor circulation, or genetics. The most common reason that nails thicken is due to a fungal infection of the nail material, also called onychomycosis. It can affect one or several nails. It can be treated if caught early.
The best way to treat fungal nails is to not let them become infected in the first place. To prevent fungal nails, do not walk barefoot in public places, such as locker rooms, indoor pools, or gyms. Use shower sandals. Treat any changes you notice in the nails early, and treat any athlete’s foot infection quickly. The fungus that causes athlete’s foot is the same fungus that affects the nails.