Why Are My Toenails Yellow And Thick?

This article was reviewed by Dr. Emilija Ashtalkoska on August 25th, 2018. Products listed therein are not intended to diagnose, treat, cure, or prevent any disease or health condition.


You are going about your daily life and everything seems normal. You look down and all of a sudden, you realize that one or more of your toenails have become yellow and thick! In every other regard, you seem to be completely healthy.

Thoughts start running through your mind –  could it be nail fungus? Or something more serious like cancer?

What could possibly cause this? Read on to find out what causes yellow and thick nails.

Toenail Fungus Is The Most Likely Culprit

Why Are My Toenails Yellow And Thick?

Unfortunately, nail fungus, also known as onychomycosis, is the most likely culprit if you are experiencing both thickening and yellowing of the nail. Other common symptoms of nail fungus include:

For many, nail fungus originates with athletes foot, also known as tinea pedis. When the fungal infection is left untreated for long enough, it spreads to the toenails.

For most people, nail fungus starts as a small white or yellow or orange patch. Eventually, the fungal infection spreads throughout the nail and then starts affecting the abutting nails.

Unfortunately, if left untreated, nail fungus can spread to other parts of the body such as the head, skin, or groin causing ringworm and jock itch.

How Did I Get Toenail Fungus?

It is estimated that over 30 million people worldwide have nail fungus, so you are certainly not alone.

Unfortunately, fungi thrive in wet and moist environments, so it is difficult to figure out exactly where your fungal infection originated. However, there are a number of common sources of infections.

Wet Places

If you have a penchant for visiting public pools, saunas, or gyms, it is likely that you contracted nail fungus from one of these locations. In the future, it is imperative that you always wear sandals when visiting these places.


Are you a diabetic? Unfortunately, diabetics are twice as likely to contract nail fungus as non-diabetics.

This is because diabetes affects blood flow to the limbs, which makes it significantly more likely that you will contract a fungal infection such as nail fungus or athletes foot.

Infected Partners Or Family Members

Do any of your loved ones have nail fungus? Unfortunately, nail fungus can spread from person to person quite easily in the right environment.

The most important thing to do in this scenario is to never share objects that come into direct contact with an infected party.

Does your Dad have a fungal infection? Never borrow his shoes. Does your partner have athletes foot? Always wear socks to bed and make sure you constantly wash your sheets.

Unsavory Salons

nail fungus salon

If you enjoy the occasional pedicure or manicure, it is important to only visit the most reputable of salons.

Unfortunately, many people contract nail fungus from salons that are lax with proper cleaning and sterilization techniques.

All it takes is for one piece of infected material to touch your nail bed, and you can contract nail fungus.

Always do proper research before visiting any salon to avoid contracting nail fungus.

Additionally, if you already have a fungal infection, make sure that your manicurist or pedicurist is fully aware to prevent it from spreading to other customers.

Injury To The Nail

Have you recently stubbed your nail? Drop something on your toe? Got your foot caught in the door?

Unfortunately, if you have ever experienced any sort of trauma to your nail or foot, it vastly increases the likelihood of contracting a fungal infection.

It is also quite possible that the inflicted trauma wasn’t a single event. If you have a pair of ill-fitting shoes that you wear frequently, that can slowly cause trauma to the nail over time.

How To Avoid Injury To The Nail

It is quite easy to avoid trauma to the nail. We recommend taking the following steps:

  • Make sure you only wear comfortable and well-fitting shoes
  • Inspect your nails daily for signs of trauma such as black spots
  • Avoid aerobic or physical activity such as running or playing rugby

Unfortunately, if you have experienced extreme trauma to the nail it may need to be removed by a podiatrist.

If you believe you have experienced nail trauma please consult a medical professional.

Take This Quiz To See If You Have Nail Fungus

This quick quiz will let you assess whether you have contracted nail fungus.

Are My Nails:

  • Thicker than they used to be?
  • Splitting?
  • Emitting a foul odor?
  • Covered in a white or yellow material?
  • Covered in spots? (Such as white, yellow, black, or green spots)

If you answered yes to any of these questions, it is likely that you have contracted nail fungus.

Nail fungus becomes harder to treat as it spreads, so it is in your best interest to start treating the infection as soon as possible.

What Are My Treatment Options For Nail Fungus?

Many people try to utilize home remedies, such as vinegar to treat their nail fungus.

These home practices are generally the most successful for sufferers who catch their fungal infections early.

However, if you have gotten to the point where your nail or nails are both yellow and thick, home remedies such as Vicks Vaporub or Listerine are not your best options. They will work to treat your fungal infection, but it could take up to a year to start seeing results.

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If your infection has gotten to the point where your nails are both thick and yellow, we recommend utilizing a powerful over-the-counter topical treatment program, such as Purely Northwest Toenail Fungus System.

The Purely Northwest System is a fantastic option because it contains three separate treatments:

  • Antifungal Soap & Body Wash
  • ReNew Toenail Solution
  • Tea Tree Oil Foot Soak

We highly recommend utilizing this treatment option. If you would like to do more research into Purely Northwest, view our full review of their 3-in-1 fungus system.

Unfortunately, nail fungus only gets harder to treat the longer the infection remains, so we recommend starting treatment as soon as possible.

Click here to view the product page for Purely Northwest directly on Amazon.com.

What Else Causes Thick Nails?

If your nails are thick, but not yellow, there is a chance that you do not have nail fungus. There are some additional factors that cause just thickening of the nails without a fungal infection.

Aging, Onychogryphosis, and family history are three of the most common factors when it comes to thickening nails.

Aging Can Cause Nails To Thicken

nail fungus elderly

For some people, thickening of the nail can be a direct result of simply aging. This process is known as Onychaucix, and fortunately, tend to not be a sign of any deeper health issues.

However, if your nails are both thick and yellow, it is most likely not due to aging alone. Unfortunately, you have contracted nail fungus and it must be treated before it spreads.


Onychogryphosis, also known as ram’s horn nails, is a condition that causes the nails to become thick and clawlike.

The condition is often called ram’s horn because in severe cases, the nails become so thick and curved that they resemble a ram’s horn.

If you believe you have developed onychogryphosis, seek medical attention immediately.

Family History

Unfortunately, a certain segment of the population has weaker immune systems due to genetics, making them more prone to fungal infections and thus more likely to have yellowing or thickening of the nails.

If any members of your family have nail fungus or any of the symptoms, it is vital that you take the utmost precaution to try and avoid every contracting an infection in the first place.

How Can I Prevent Thick And Yellow Toenails?

There are a variety of things that you can do to prevent contracting nail fungus, and thus thickening and yellowing of the nails.

  • Always wear sandals in wet places such as showers or saunas
  • Rotate your shoes regularly
  • Clean your socks and sheets with antifungal solutions
  • Always dry your feet after showering
  • Clip your toenails regularly

Perhaps most importantly, if you believe you have nail fungus treat your fungus at the first sign of infection.

When properly treated, it can prevent the nails from thickening or turning yellow in the first place.


If your nails have turned yellow and have started to thicken, you most likely have nail fungus. But do not worry!

There are a variety of fantastic treatment options that you can utilize to get your nails back to their former glory. Thank you for enjoying the contents of this article, and we wish you the best of luck with your fungus fighting journey.

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Sources for more information on nail fungus:

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