Thick Yellow Toenails


Do you want to wear flip-flops but are embarrassed by thick yellow toenails? Thick yellow toenails are just what their name implies – a rather unsightly condition that might have you reaching for shoes instead of sandals. But instead of focusing on their unpleasant appearance, we want to help you get to the bottom of what causes this condition so you can treat it – or even better – prevent it!

What causes thick yellow toenails? 

Why do toenails become thick and yellow? 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, particularly by fungi.

You might remember from Biology 101 that fungi like warm, dark, and moist places to grow. Unfortunately, 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. Gross but true! 

How do fungi get into my toenails? 

As you know, it’s easy to crack a toenail when running, playing tennis, or simply 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. Yikes! 

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? 

Self- Assessment Quiz 

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. 

Are There Any Serious Concerns? 

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? 

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, avoid or reduce activities that risk toenail damage (or at least make sure your feet are well-protected). 
  • Wearing shoes that fit well. 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, and firm rear-foot 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. 
  • 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. You can use sprays with solutions such as Lamisil or Tinactin, or even Lysol, to effectively prevent fungi in shoes. (Avoid antifungal powders because 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 anti-fungal medicines such as Tolnaftate. 

      • Take oral anti-fungal 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. Wash your socks after every use. 

      • Rotate your shoes so that you’re not wearing the same shoes 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. 

      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 – and get rid of the fungus forever. Sandals, here you come! 

      This information is not intended to be a substitute for professional medical advice, diagnosis or treatment. Please consult your health care provider on all matters relating to this or any other condition that may affect your health.