Thick Toenails

While toenails protect your toes, they can sometimes become too thick. When your toenail is too thick, it can become a cosmetic and health issue. Although your toenails get thicker as you get older, fungal infections, injury or mechanical damage, and certain diseases can cause excessive thickness. Toenail fungus (also known as onychomycosis) accounts for half or more cases of thick toenails and affects 8% to 10% of the population.

Symptoms of thick toenails can vary depending on the underlying cause. Thick toenails can also become chronic, especially if left untreated. Fortunately, treatments can help improve symptoms. But, your exact treatment plan will depend on the severity of the condition. Prevention strategies can also help you lower your risk of developing thick toenails in the future.

Types

When diagnosing and treating thick toenails, healthcare providers may break the condition down into different types based on whether it is a fungal infection and how the toe looks. Common types of thick toenails include onychomycosis (a type of nail infection), onychauxis (a form of nail overgrowth), and onycholysis (when the nail separates from the nail bed).

Onychomycosis

Onychomycosis is the most common toenail fungus. The infection directly affects the nail bed on a toenail. The nail matrix (the area where your nail grows) may thicken to remove the fungal infection from your toe by starting the growth of a new nail.

Onychauxis

Injuries and a wide range of conditions like psoriasis and diabetes can result in onychauxis, also known as onychogryphosis. Most often affecting people older than 65, onychauxis causes abnormal thickening and growth in your toenails. You may also notice your nail turning a different color, most often a yellow or brownish tint. Over time, the nail plate separates from the nail bed and can start to curl and resemble the shape of an oyster.

Onycholysis

Onycholysis occurs when the nail plate painlessly separates from the nail bed. This condition can develop from a nail injury, an allergic reaction, psoriasis, or other conditions. Repeated trauma to the nail from over-filing or an allergic reaction is one of the most common causes of onycholysis.

Symptoms 

Toenails are usually 1.4 millimeters (mm) thick in people assigned female at birth and 1.65 mm thick in people assigned male at birth. When nail plates thicken, there may be changes in how your nails look and feel. Depending on the underlying cause, you may also feel pain or discomfort if the cause is more severe.

Changes in Appearance

If caused by onychomycosis (toenail fungus), you may notice a yellow, green, or brown color on your nail. If it's from onycholysis—the nail lifting from the nail bed—your nail may appear lighter, white, or yellow. There may also be white buildup on the top of your nails, or building up beneath them.

Your toenails will have a distinct, curled appearance, and appear discolored if you have onychauxis. They may curl and grow long, similar to ram horns. Some cases of thick toenails can escalate to yellow nail syndrome, a rare autoimmune disorder that causes nails to grow yellow as they thicken.

Changes in Texture

Thick toenails can also change how your toenails feel. Commonly, they develop a rougher texture that can make them more difficult to care for. It may be more difficult to trim your toenails if they become brittle and grow back unevenly. In addition, your toenails may flake or crumble when you attempt to trim or file them.

Changes in Odor

Fungal infections of the toes can affect the way your toes smell. You may notice a cheese-like odor coming from your toenail. If a thickened toenail becomes ingrown (when the nail grows into surrounding tissue), bacterial or fungal infections can also cause foul discharge (pus that oozes out of your skin).

Other Symptoms

Though often not painful on their own, thick toenails can also cause pain and discomfort when you wear shoes—especially if they are tight-fitting. Your feet may not fit the same shoes if the thicker toenail sticks out from your foot. This can increase pressure on the toes and make walking feel painful.

What Causes Thick Toenails? 

Toenails get thicker when the keratin (a protein that naturally occurs in your body) cells that make up the nail plate (the visible part of the nail) excessively grow on top of each other. In addition to conditions that can cause this buildup, toenails can get thicker naturally as you age and can be inherited. This is because in older adults the nail matrix—the lighter half-moon shape you can see at the base of your nails—is not as good at getting rid of dead keratin cells.

Underlying conditions that can cause your nails to get thicker include:

• Limited blood circulation: Foot injuries or shoes that are too tight can prevent your foot from having enough space for blood to comfortably circulate, especially when sitting for a prolonged amount of time.
• Fungal toe infections: Small fungi make contact with your skin and cause a contagious infection commonly passed in showers or other wet surfaces.
• Autoimmune Disorders: Lichen planus and psoriasis are autoimmune disorders that cause skin cells to multiply too rapidly which can cause thickened nails.
• Paronychia: An infection of the nail commonly caused by biting or picking at your nail.

Risk Factors

While anyone can experience thickened toenails, some factors can increase your risk:

• Not having proper foot hygiene habits
• Trimming nails poorly
• Being older than 65
• Wearing shoes that don’t fit well
• Swimming
• Using public showers or pools
• Getting a foot injury that damages the toenail
• Experiencing athlete’s foot
• Having frequent pedicures or nail salon treatments
• Living with conditions that affect the immune system or cause poor circulation and venous insufficiency
• Taking medications that lower immune system function
• Undergoing chemotherapy or radiation therapy treatments
• Smoking tobacco

Diagnosis  

If you notice your toenails looking thicker than usual, speak with your healthcare provider. They may refer you to a podiatrist (a doctor specializing in foot conditions). They will want to rule out other potential causes of symptoms, such as having an allergic reaction, cancer, or hypothyroidism (underactive thyroid).

To learn more about your symptoms and the underlying cause of your condition, your provider will likely also order additional diagnostic tests, like:

• Visual screening: Use a dermatoscope, or hand-held magnifying glass to visually assess your nail.
• Clip biopsy: Clips off a small piece of your toenails to perform a biopsy and determine the cause of an infection.
• Swab testing: Takes a swab of your toenail to check for signs of infection. 

Treatments

Thick toenails are often chronic and can be difficult to treat. There’s no quick fix, and unfortunately, it can take more than a year for toenails to grow back healthy. This may seem frustrating, but removing the underlying infection or cause of your symptoms will improve your nail health in the long run. To improve your condition, your healthcare provider may recommend topical creams, medications, and other therapies.

Topical Agents

For toe fungus, medicated creams available over-the-counter (OTC) may help control mild cases. Several ingredients in OTC products are approved by the United States Food and Drug Administration (FDA) for use. These ingredients include:

• Calcium, copper, or zinc undecylenic acid
• Clioquinol (3%)
• Haloprogin (1%)
• Miconazole nitrate (2%)
• Povidone-iodine (10%)
• Tolnaftate (1%)
• Clotrimazole (1%)

Antifungal Medication

If you have a mild to moderate fungal infection, your healthcare provider may prescribe you a topical antifungal medication. Oral medications are also effective for more severe cases. These include: 

• Lamisili (terbinafine)
• Sporanax (itraconazole)
• Jublia (efinaconazole)
• Kerydin (tavaborole)
• Ciclodan (ciclopirox)

Psoriasis Medications

Nail psoriasis can also be treated with topical, oral, or injected medications, including:

• Corticosteroids, such as Triderm (triamcinolone acetonide)
• Kenalog (triamcinolone acetonide)
• Topical vitamin D
• Retinoids, related to vitamin A, such as acitretin  
• Biologics, such as Simzia (certolizumab pegol) and Humira (adalimumab)  
• Immunosuppressants, such as Otrexup (methotrexate) or Neoral (cyclosporine)

Debridement

In severe cases, or if medications are causing too many side effects, dermatologists (doctors specializing in skin, hair, and nail conditions) may decide on debridement. This is a medical procedure that involves removing build-up and affected toenails. Sometimes, your dermatologist may consider avulsion—or, the removal of the entire toenail, to allow for healthy regrowth.

Laser Therapy

Laser therapy is a type of treatment where lasers apply heat to the fungus on your affected nail. The FDA only recommends this as a short-term treatment to improve appearance. More research is needed to know how effective and safe this treatment truly is in the long term.

Complementary Approaches

Alongside medical treatments, there’s evidence that some complementary approaches may also be helpful:

• Tea-tree oil: Researchers found evidence that regularly applying diluted tea-tree oil, a plant extract, was effective for mild cases of onychomycosis, especially alongside antifungal medications.
• Vick’s VapoRub: Daily use of Vick’s VapoRub, an OTC topical ointment for cough, may also be effective. In a formative study, researchers saw 83% of participants have improvements in the appearance of their nails after 48 weeks of treatment, with 27.8% seeing a complete cure. 

How To Prevent Thick Toenails

To avoid getting thick toenails or lower your risk of another thick toenail, there are several preventative strategies you can use. Consider the following methods to protect your feet:

• Wearing properly-fitting, comfortable shoes that are neither too tight nor too large
• Protecting your feet in shared, wet spaces, such as gym showers or locker rooms
• Keeping your feet clean
• Changing socks regularly
• Cleaning and disinfecting socks and shoes
• Trimming nails often
• Avoiding sharing nail clippers or sterilizing nail clippers with alcohol if you are sharing
• Treating athlete’s foot
• Refraining from removing buildup beneath your toenails yourself

Complications

While thick toenails aren’t dangerous, if untreated, they can get worse and lead to several more serious complications:

• Cellulitis: A bacterial skin infection that causes redness, pain, and swelling. Onychomycosis and cellulitis are often linked to compromised immune function.
• Loss of toenail: Over time, fungal infections, psoriasis, and other conditions can cause your nails to crumble away or completely detach.
• Sepsis: Also known as “septic shock,” sepsis is a potentially fatal, full-body immune response to infection.
• Osteomyelitis: Some fungal infections can also spread to your bones, leading to pain, chills, and bone loss. As with other complications, this is more common if you have a weakened immune system.
• Tissue damage: Another complication of untreated nail psoriasis and onychomycosis is permanent tissue damage around your toenail. Pain and discomfort from these conditions can also affect your ability to walk or function.  

A Quick Review

Depending on the cause, if you have a thick toenail it may also appear discolored and change in shape. Thick toenails are generally harmless, but in more severe cases your toenail can detach from the toe or cause pain. Though it takes time for healthy toenails to regrow, treatment options like OTC medications, laser treatments, and home treatments are available to improve symptoms. If you’re concerned about your thick toenails or experience discomfort, speak with your healthcare provider to learn what treatment options are right for you.