Healthy nails are clear in color and smooth, without cracks, indentations, or ridges. Yellow toenails can be caused by aging, nail polish, or an infection.

Read on to learn about the causes of yellow or discolored toenails, as well as home remedies, medical treatments, and when you should get help from a medical professional.

Aging can be a natural cause of yellow toenails and fingernails. As people grow older, the color, thickness, and shape of their nails tend to change. As we get older, we will often have a more yellow color to our nails, as well as brittleness, and changes in texture.

According to an older 2016 study, nail plate discoloration is one of the most common side effects of using cosmetic products on your nails. The discoloration most often appears as red or yellow. It’s harmless and typically resolves on its own after all traces of their nail polish have been removed.

Taking a break from painting your nails should make the yellow go away.

Having yellow toenails isn’t typically considered dangerous by itself. However, if the cause for the yellow toenails is an underlying medical condition, it may be a sign that something is wrong. For example, yellow toenails can be caused by a fungal infection or medical disorder.

Yellow nail syndrome (YNS)

In rare cases, yellow toenails can actually be a sign of YNS. People with the condition have yellow, curved, thickened nails that grow slowly, along with other symptoms like respiratory problems. Their nails also may have ridges or indentations in them and can also turn black or green.

YNS primarily affects adults 50 and older, but it’s been seen in children. Doctors don’t know what exactly causes YNS, and the condition is often misdiagnosed. Early diagnosis is crucial for effective management.

Fungal infection

Another common cause of yellow toenails in an infection by a fungus that attacks the nails. This is called onychomycosis, and it happens more in adults than children. It can lead the nail to turn yellow, have yellow spots, white patches, or even turn black.

The fungal infection is caused most often by dermatophytes, which break down keratin. Keratin is found in skin and nails. Onychomycosis occurs in about 10% of the adult population, and about 50% of all nail disease. The risk of getting it increases with age. About halfof people over the age of 70 get the fungal infection.

Some people are more prone to getting yellow toenails or catching a fungal infection. If you have a medical condition that causes poor blood circulation in the legs, like diabetes, peripheral vascular disease, or other autoimmune disorders, you’re more prone to foot disorders in general.

Athletes or people who spend a lot of time in hot or moist conditions are also more prone to getting a fungal infection.

Make an appointment to see a medical professional if you have the following signs of YNS or a nail infection, such as:

  • change in shape or thickness
  • any bleeding
  • discharge
  • pain
  • swelling

Additionally, it’s suggested you see a primary care doctor or dermatologist if changes in the appearance or texture of your toenails are making it more difficult or uncomfortable to walk or perform daily activities. A dermatologist is a doctor who specializes in conditions of the skin, hair, and nails.

In most cases, yellow toenails are treatable. There are some medications and home remedies that might help cure yellow toenails or help lighten the yellow color. What treatment your doctor recommends will depend on what’s causing the yellow nails.

Medical treatments

If your yellow toenails are being caused by a fungal infection, you’ll need antifungal medication to treat it. One of the most common prescription antifungal medications is ciclopirox 8% solution (Penlac and Cicloda), which is applied to the nails like nail polish.

Home remedies

Two nonprescription home remedies that have been studied to treat yellow toenails are Vicks VapoRub (a topical mentholated ointment) and tea tree oil.

A 2022 review of several studies suggests there is not enough current evidence that tea tree oil is an effective complementary treatment for fighting off a fungal infection. While several older studies have pointed out its potential, they were too small in scope and of poor quality, the review noted.

Several smaller studies, such as one from 2024, have noted that Vicks VapoRub and another cough suppressant, TCS, does have potential as a complementary treatment. Of 18 participants, 83% were cured of the infection. However, much more research is needed.

You may not be able to prevent yellow toenails from ever happening again, but your best bet is to practice proper nail care and regularly inspect and monitor your nails for any signs of an issue, especially if you have poor circulation or are prone to nail disorders. Be sure to:

  • Always wear properly fitting shoes. Have your shoe size fitted by a professional if you’re unsure of your correct shoe size. Feet can change in shape and size with weight gain, loss, or pregnancy.
  • Cut toenails straight across with clean nail clippers.
  • Keep nails clean and dry.
  • Be careful when choosing a salon for a pedicure and check to make sure that they’re changing water and sanitizing stations between customers.
  • Regularly air out your shoes after sports or other outdoor activities to ensure that they’re not wet while you wear them.
  • Always wear clean socks.

In some cases, yellow toenails may be a result of nail polish or the normal aging process, but just to be on the safe side, you should regularly monitor your nails for any changes.

Most cases of yellow toenails are caused by a fungal infection that’s treatable. If you notice that your nails are turning yellow — and especially if you have any other issues like a change in shape or thickness or any bleeding, discharge, pain, or swelling — you should see a doctor.