Why Are My Toenails Yellow? Here Are 4 Likely Causes

While toenails should be clear, some people look down and find themselves asking questions such as: “Why are my toenails yellow?“, “What causes yellow toenails?“, “Why are my toenails discolored?“ and “Why is my toenail black?“

Yellow toenails, discolored toenails, dark toenails, or thick and yellow toenails can be quite concerning, aside from being aesthetically undesirable.

In this article, we will discuss what causes yellow toenails, what it means if your toenails are yellow or discolored, why some people have thick toenails, and what to do if you have yellowish toenails or thickened toenails.

We will look at: 

  • Why Are My Toenails Yellow?
  • What Causes Yellow Toenails?
  • How to Treat Yellow Toenails

Let’s get started!

Yellow toenails.

Why Are My Toenails Yellow?

Before we look at what causes yellow toenails, let’s cover what healthy toenails should look like.

Healthy toenails should be clear or very mildly opaque in color. They should be smooth without cracks or noticeable ridges or indentations.

Discolored toenails, yellow toenails, black toenails, dark toenails and thick or scaly toenails are abnormal.

So, is it bad if your toenails are yellow? Are yellow toenails bad?

Generally speaking, yellow toenails are a sign of an underlying condition or problem that should be addressed.

Even more so if the toenail discoloration is accompanied by a thickness or change in the texture of your toenail such as cracks, ridges, or visible layers when you look at the toenail from the tip of your toe, or discomfort, bleeding, and brittleness.

Yellow toenails.

The good news is that yellow toenails are not always a cause for concern. 

Some amount of toenail discoloration can be normal in certain circumstances, and most of the causes of toenail discoloration are not serious medical conditions with poor outcomes.

However, if you notice that your toenails are yellow or you have discolored and thickened toenails, you should speak with your doctor about the causes and treatments for yellow toenails.

What Causes Yellow Toenails?

What does it mean if your toenails are yellow?

Here are some of the common causes of discolored toenails, such as yellow toenails or black toenails:

Yellow toenails.

#1: Aging

One of the most common causes of yellow toenails and yellow fingernails is aging. In this case, discolored toenails are normal and natural and not a cause of concern.

The aging process is accompanied by many physical changes, one of which is a change in the color, thickness, texture, and shape of the toenails and fingernails.

Therefore, if you are an older adult and have noticed that your toenails are slowly becoming yellow over time, this is likely a normal and natural part of getting older.

#2: Stained Toenails from Nail Polish

One of the most innocuous causes of yellow toenails, tan toenails, or brownish toenails is from frequent application of nail polish.

If you often paint your toenails with red, orange, brown, or purple nail polish, you can have yellowing toenails or a discolored amber toenail color.

Nail polishes contain harsh chemicals, which, along with the pigments, can penetrate the keratin layer of the toenail over time.

If you are frequently painting your toenails, there could be some residual lingering discoloration of the surface of the toenail from the nail polish.

Taking a break from using nail polish can help prevent your toenails from yellowing or discoloring and may help resolve yellow toenails once you notice the problem has already set in.

Toenail fungus.

#3: Toenail Fungus

Aside from changes in the color of your toenails and the texture that occur with advanced age, the most common cause of yellow toenails is toenail fungus, also known as a fungal infection of the toenails.

With toenail fungus, a fungal species attacks and colonizes the toenail.

These fungi species are typically dermatophytes, which eat keratin to grow. 

Keratin is the hard structural protein that forms toenails and fingernails, along with other structures like your hair and certain skin cells.

Toenail fungus is referred to as onychomycosis, and this toenail condition is notoriously difficult to treat because the toenail fungus is aggressive and resistant to most toenail fungus treatments.

Fungal infections of the toenail can happen to people of any age, though it tends to be more common in older adults as well as those with compromised immune systems because the fungus is an opportunistic invader.

Toenail fungus.

Onychomycosis is also more common in athletes due to the fact that fungi like to breed in warm, moist, dark environments.

Therefore, if you are frequently wearing sweaty socks or spend a lot of time with your feet in sneakers where sweat and bacteria build up, you are more likely to develop fungal infections of the feet, such as athlete’s foot and toenail fungus.

Additionally, there are other risk factors for toenail fungus, such as diabetes, cardiovascular disease, certain autoimmune conditions, and peripheral arterial disease, as all of these conditions impede circulation to the feet.

This compromises the general health of the toes and toenails, which can increase your risk of fungus infecting the toenails.

Toenail fungus symptoms include:

  • A yellowing of the toenails or discoloration of the toenails
  • Thickening toenails
  • A visible buildup of crusty layers underneath and on top of your toenails
  • Ridges on toenails
  • Ripples on toenails
  • Brittle toenails that crack or shatter, especially when you try to cut them or the ram into the end of your shoe
  • Malodorous toenails that have an off-putting funk
  • Toenails that curl either longitudinally or horizontally
Toenail fungus.

If you have a fungal infection of the toenails, it is often quite difficult and painful to cut your toenails, and you may experience bleeding when using toenail clippers. 

The fungus toenails may be too thick to cut with basic toenail clippers, as the fungus builds up underneath and through the layers of the toenail, raising the toenail off of your nail bed and increasing the thickness and brittleness of the yellow toenail.

#4: Yellow Nail Syndrome

While the primary yellow toenail cause is a fungal infection of the toenails, there is a relatively rare condition known as yellow nail syndrome (YNS) in which the fingernails or toenails turn yellow.

Usually, if you have yellow nail syndrome, the toenails will also thicken and curl, and there may be indentations on the toenails or notable ridges on toenails that make the toenails prone to cracking and breaking.

The toenail indentations can even turn green or black over time.

In severe cases, yellow nail syndrome can result in bleeding toenails, discharge from toenails, swelling around the toenails, and painful toenails, particularly when you try to cut or press on your toenails.

Yellow nail syndrome is sometimes accompanied by respiratory symptoms in addition to changes in the texture, growth patterns, and appearance of the toenails and fingernails. 

Unfortunately, the medical community still doesn’t have a strong grasp on what causes yellow nail syndrome.

That said, if you have been diagnosed with yellow nail syndrome, it is important to keep a close eye on the integrity of your toenails, and if you are experiencing bleeding toenails, painful toenails, or ulcers in your toenails, you should see your doctor as soon as possible.

A doctor treating a yellow toenail.

How to Treat Yellow Toenails

Treating yellow toenails will depend on the cause of the toenail discoloration issue.

If you have an underlying medical condition, these will need to be addressed in order to restore proper circulation to your toenails.

The age-related changes to your toenails are normal and natural. 

Trying to keep your body healthy and as biologically young as possible can help stave off premature yellowing of toenails.

Getting regular exercise, following a nutritious diet, reducing stress to keep your blood pressure in check, and practicing good foot hygiene are all ways to help prevent your toenails from turning yellow early.

Toenail fungus can be treated with prescription medications and/or home remedies.

The most common toenail fungus medication is Lamisil, which is an antifungal drug that may help cure toenail fungus. 

Toenail fungus.

However, this medication is hard on the liver, so you will need to get routine blood tests and have a healthy liver in order to take this medicine.

Studies have found that antibiotics can be helpful for treating yellow toenails, particularly if there is an underlying infection such as pneumonia. 

There are also some home remedies or OTC treatment for toenail fungus, such as applying tea tree oil as if it was nail polish, applying topical corticosteroids that contain vitamin D3, using vitamin E oil, or using Vicks VapoRub (a topical mentholated ointment).

While most of the home remedies for toenail fungus have not been found to be particularly effective, there is some evidence to suggest that Vicks VapoRub improves yellow toenails in about 25% of people who apply it consistently on and around the yellowed toenails.

Finally, it’s worth mentioning that proper hygiene of your feet is important for preventing fungal infections of the toenail.

Keep your feet clean and dry. Change sweaty socks as soon as possible and allow your feet to air out overnight or whenever you do not need to be wearing footwear.

If you are suffering from Athlete’s Foot and are looking for an essential oil remedy, click here.

A bottle and dropper of essential oils.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.