Changes in your toenails may be a sign of an underlying condition. Toenails that have grown thicker over time likely indicate a fungal infection, also known as onychomycosis. Left untreated, thick toenails can become painful. Prompt treatment is key to curing the nail fungus. Fungal infections can be difficult to cure and may require months of treatment.

A change in the thickness of your toenails may be just one symptom of a fungal infection.

Other symptoms of nail fungus include:

  • toenails that change in color to yellow, brown, or green
  • a foul odor that comes from the toenail
  • toenails that can lift up from the nail bed
  • toenails that split or crumble
  • toenails that look scaly or chalky
  • toenails with dirt and other debris under them

You may notice no discomfort in the early stages of the infection. As symptoms build, your toenails may become painful.

Nearly 20 percent of the adult population has onychomycosis. This condition occurs when a fungus or yeast enters your toenail:

  • where your toenail and nail bed meet
  • in a crack in your toenail
  • in a cut in your skin that touches your toenail

The fungus or yeast grows under the nail bed, where it’s moist. The infection is initially minor, but with time may spread and cause your toenail to grow thicker as well as cause other symptoms.

Your toes are very susceptible to a fungal infection because they’re frequently exposed to wet areas. Moisture helps fungus spread.

You are more likely to contract toenail fungus from:

  • being barefoot in public places with wet floors, such as swimming pools, showers, and gyms
  • frequent or prolonged exposure to water
  • shoes that constrict your feet
  • sweaty feet and shoes
  • damage to a toenail
  • athlete’s foot that spreads to your toenails
  • medications that suppress your immune system
  • genetics
  • smoking

You may also be more likely to contract toenail fungus if you have a pre-existing medical condition, such as:

Cancer treatments may increase the likelihood of developing nail fungus. If you have a pre-existing condition and develop fungus, it’s very important to treat it as soon as possible.

See a doctor if you notice a change in the appearance of your nails. Treating a fungal infection in its early stages will help prevent the condition from worsening.

Your doctor will look at your nails to diagnose the condition. The doctor may also take a swab underneath the nail or take a toenail clipping to diagnose the condition.

Untreated toenail infections can cause some complications. Over time, the infection can get worse, and symptoms may become more severe. Toenails can thicken to the point that they cause discomfort when you try to wear shoes or even make it more difficult to walk.

If you have pre-existing medical conditions, treatment is vital so the fungus doesn’t contribute to secondary infections or complications.

Although not all cases of toenail fungus need to be treated, thick toenails may be a sign that the fungus has gotten worse. Several methods are available to treat your toenails. You can try some home-based treatments first and then talk to your doctor about prescription-based options. Topical and oral medications are the mainstays of therapy.

Home-based treatments

You can try a variety of home-based methods to treat nail fungus:

  • Clean the affected area with soap and water daily.
  • Groom your nails regularly. Soften your nails first by applying urea cream (Aluvea, Keralac) and wrapping your feet in bandages at night. Then wash off the urea cream and use a nail clipper and nail file to trim your nails.
  • Apply an over-the-counter fungal treatment after you gently file your nails.
  • Apply Vicks VapoRub on your toenail each day. This may help the infection subside.
  • Apply snakeroot extract to the toenail every third day for one month, twice a week in month two, and then just once a week in month three.
  • Apply tea tree oil twice a day every day.

Medical treatments

Toenail fungus may require medical interventions as prescribed and recommended by your doctor. These include:

  • topical medications
  • oral medications
  • laser treatments
  • removal of the toenail to treat the nail bed

Treating toenails for fungus may require you to stick to the treatment plan for several months. Toenails grow slowly, and they can take 12 to 18 months to grow out.

You may experience a recurrence of toenail fungus after treatment. If you’ve treated your fungus and want to avoid it from coming back, you can try methods to prevent it from growing in your toenails again.

You can prevent thick toenails or the recurrence of toenail fungus in several ways:

  • Keep your feet clean by washing them with soap and water regularly. Dry them off with a towel afterward.
  • Keep your feet as dry as possible: Change your socks a few times a day, wear cotton socks that remove moisture from your feet, rotate your shoes so they can dry out, and purchase shoes that breath and don’t constrict your feet.
  • Try a foot powder that keeps your feet dry.
  • Wear flip-flops or other shower shoes when you are in locker rooms or at the pool.
  • Groom your feet properly. Your toenails shouldn’t grow beyond the end of your toe.
  • Make sure to use disinfected tools when trimming your nails.
  • Purchase new footwear if you’ve recently cured your nail fungus.