Thick Yellow Toenails

Photo of a person's foot with thick yellow toenails

Do I have thick yellow toenails?

Because of an unsightly condition called thick yellow toenails, you might avoid activities such as taking a pleasant walk on the beach in your flip-flops, or strolling through a park in your sandals. While you might feel embarrassed and instinctively want to cover up your feet, how your feet look should be the least of your worries.

There are more serious causes behind this condition and, as you will read, covering up your feet may actually harm you more than help you.

What causes thick yellow toenails?

Photo of old athletic shoes that may breed fungi

Sometimes, toenails naturally thicken as people get older. Combined with diminished blood supply, your nails can grow more slowly, thicken, and become increasingly susceptible to infection. While thick yellow toenails look awful, you shouldn’t just view this condition by how your toenails look. That’s because another culprit behind this condition is often fungi—and the laws of how fungi normally grow can also apply to your toenails.

You might remember from Biology 101 that fungi like warm, dark, and moist places to grow. That includes places such as your shoes, socks, and stockings. When you wear your shoes or socks all day, leave them in damp, dank places, or expose them to moist conditions (like high humidity or rain), fungi are more prone to grow.

How do fungi get into my toenails?
Photo of a person standing barefoot in a public shower

As you know, it’s easy to crack a toenail when running, playing tennis, or simply just banging or stubbing your toe. A toenail crack gives fungi an opening and a place to live. Once inside your toenail, it’s extremely hard to get rid of a fungus. That’s because your toenail—almost like a Band-Aid or cast—keeps the fungus in place. With nowhere for the fungus to escape or get naturally cleaned out, it stays…and grows.

You increase the likelihood of acquiring a nail fungus by frequenting health clubs, using community showers, or sharing emery boards.

Think you might have a nail fungus that's resulted in thick yellow toenails? TAKE THIS SELF-ASSESSMENT
Self- Assessment
Are my toenails:
  • Discolored? (Especially note if they are green, yellow, or a darker color.)
  • Thick and flaky?
  • Filled with debris under the nail that smells really bad?
  • Splitting?
  • Filled with pit marks?

If your toenails show any of these symptoms, you may have thick yellow toenails caused by a fungus. Read about treatment and prevention tips from the experts at FootSmart

Are there any serious concerns?
Photo of a podiatrist examining foot for toenail fungus

Sometimes, thick yellow toenails indicate that you may have a hard-to-diagnose foot condition. In some cases, your podiatrist might take a biopsy of the alleged fungus and have it analyzed by a pathologist. The pathologist will first check to make sure you are not suffering from psoriasis, eczema, dermatitis, or another kind of skin condition. To confirm the diagnosis of a fungal infection, you may take a KOH (potassium hydroxide) test and Periodic acid-Schiff (PAS) test. These are accurate, scientific chemical tests that ensure a proper diagnosis of your specific fungal infection.

How do I treat and prevent Thick, yellow toenails?
Photo of a man cutting his toenails to help prevent thick yellow toenails

While thick, yellow toenails might be hard to treat, there are some important ways to fight off and prevent this condition.

First, prevent thick yellow toenails and nail fungi by:

  • Avoiding injury to your toenails. Since a crack in your toenail is one of the most common ways that a nail fungus begins to take root, lessen any activities that risk toenail damage (or at least make sure your feet are well-protected).
  • Wearing well-fitting shoes. Make sure plenty of space exists between the end of your shoe and the tip of your longest toe. This extra space helps prevent damage to your toenails caused by any shock or impact. Also look for shoes with:
    • Thick, rigid soles
    • Extra arch support
    • Firm rearfoot control
  • Avoiding shoes or boots that trap and retain moisture, such as rubber boots.
  • Keeping your feet dry by changing your socks if they become wet or damp, and leaving your shoes out in dry places when you’re not wearing them.
  • Using thongs or flip-flips in public places to avoid contact with fungi. To be especially careful, you may even want to avoid walking barefoot anywhere, even around your house or yard.
  • Clip your toenails regularly to avoid cracking or chipping.

If you’re already diagnosed with thick yellow toenails, currently fighting off a nail fungus, or prone to a reoccurrence of nail fungus, you can treat this condition by doing the following:

  • Spray your shoes with an over-the-counter topical anti-fungal spray. Fungal spores that remain in your shoes can reinfect your nails if you’re not careful. You can use sprays with solutions such as Lamisil or Tinactin, although places like bowling alleys often use Lysol to effectively prevent fungi in shoes. (Avoid antifungal powders, since they tend to deteriorate the soles of shoes rather quickly.)
  • Use nail gels, oils, or other solutions that help break down and clean out the keratin debris that builds up underneath your nails. Keratin is the material your body creates to make skin, hair, and nails, and it’s this debris that often causes the discoloring of your toenails.
  • Use topical liquid or cream treatments that contain over-the-counter antifungal medicines such as Tolnaftate.
  • Take oral antifungal medications, but be careful about their strength. Since fungal infections require strong medication, you could experience adverse side effects.
  • Clean your socks regularly. When wearing socks, make sure they are dry.
  • Rotate your shoes so that you’re not wearing the same ones every day. Give each pair of shoes at least 24 hours to dry out, and wear them every other day.
  • Thoroughly dry your feet between your toes, especially after a shower or activities that cause you to sweat.
Photo of a person with toenail fungus despite home treatment

If the fungus or thick yellow toenails persist despite your own treatment attempts, we recommend that you see a podiatrist for additional treatment. Your podiatrist may run some tests, more accurately diagnose your condition, and prescribe a stronger medication to fight off the fungus. Since there are 17 different organisms that can cause nail fungus, your podiatrist can work with you to find the right customized treatment.