Thick Yellow Toenail After 60: Fungus, Age, or Something Else?

Common, and often misread

You take off your sock and there it is again. The big toenail is thicker than it used to be, and it has turned a dull yellow. Is it age, or is it fungus? The honest answer is that you cannot tell just by looking.

Nail fungus is common later in life. The American Academy of Dermatology (AAD) says it is rare in kids, but the likelihood increases with age, and about 50 percent of people over 70 develop it. It often starts on the big or second toe.

Here is the part many people miss. The AAD says that approximately half of nails with suspected fungus do not have a fungal infection. Another nail condition, such as nail psoriasis or a nail injury, sometimes looks like nail fungus.

Sources

• American Academy of Dermatology, "Nail fungus: Causes"
• American Academy of Dermatology, "Nail Fungus: FAQs"
• American Academy of Dermatology, "Choosing wisely: Recommendations about treatments, tests, and procedures"
• American Academy of Dermatology, "Nail fungus: Diagnosis and treatment"

What age and injury can do

Some of what you see may simply be the nail getting older. MedlinePlus says nails grow more slowly with age. They may also become yellowed, and toenails in particular may become hard and thick.

MedlinePlus also says some nail changes can be caused by infections, nutritional problems, trauma, and other problems.

Injury matters in another way too. The AAD lists a nail injury or a bunion among the things that raise your chance of getting nail fungus. MedlinePlus adds minor nail injuries and diabetes to its list of risk factors. So it is worth asking what shoe has been pressing on that toe.

Sources

• MedlinePlus, "Aging changes in hair and nails"
• MedlinePlus, "Aging changes in nails"
• American Academy of Dermatology, "Nail fungus: Causes"
• MedlinePlus, "Fungal nail infection"

What nail fungus looks like

The American Podiatric Medical Association (APMA) describes toenail fungus as an infection underneath the surface of the nail. As it takes hold, the nail often turns darker and smells bad. Debris may collect under the nail, and white marks often appear on it.

The AAD lists common signs such as a color change, a thickened nail, a nail that lifts, a brittle nail that cracks or crumbles, and a misshapen nail. Nail fungus is usually painless, which is one reason people wait. But the AAD says it almost never goes away on its own, and it can spread.

The APMA says toenails are especially exposed in damp places where you are likely to walk barefoot, such as swimming pools, locker rooms, and showers.

Sources

• American Podiatric Medical Association, "Toenail Fungus"
• American Academy of Dermatology, "Nail fungus: Signs and symptoms"
• American Academy of Dermatology, "Nail Fungus: FAQs"

How a doctor tells the difference

The AAD describes how a dermatologist checks. The doctor may take a small sample by removing some buildup from the nail, clipping off a bit of the nail, or scraping its surface. The sample is looked at under a microscope. This helps make sure it really is nail fungus.

MedlinePlus says the same: a provider examines your nails, and the diagnosis can be confirmed by looking at scrapings from the nail under a microscope. That small test means knowing instead of guessing.

Guessing can cost a lot of time, because nails grow slowly. MedlinePlus says it may take up to a year for a new clear nail to grow. The AAD adds that until the nail grows out, you will still see discoloration and other signs, even after the fungus clears. If the cause was never fungus, a year can pass with nothing changing.

Sources

• American Academy of Dermatology, "Nail fungus: Diagnosis and treatment"
• MedlinePlus, "Fungal nail infection"

At home, without making it worse

The APMA calls proper hygiene and regular inspection of your feet and toes the first lines of defense against fungal nails. Wash your feet with soap and water and dry them thoroughly, especially between the toes. If your shoes get wet, let them dry out completely before you wear them again, to help keep fungus from growing.

The APMA also advises disinfecting the tools you use to cut your nails, and not putting polish on nails that look infected, such as discolored nails. The AAD says it is common for people who live in the same home to pick up the fungus, and it suggests disinfecting your nail clippers after each use.

Once you have had nail fungus, the AAD says you have a greater chance of getting another fungal nail infection. So these habits are worth keeping.

Sources

• American Podiatric Medical Association, "Toenail Fungus"
• American Podiatric Medical Association, "Athlete's Foot"
• American Podiatric Medical Association, "Summer Foot Care"
• American Academy of Dermatology, "11 tips to prevent nail fungus"
• American Academy of Dermatology, "Nail fungus: Diagnosis and treatment"

When to stop guessing and go

The APMA says to visit a podiatrist when you notice any discoloration, thickening, or deformity of your toenails. It says the earlier you get professional care, the better your chance of getting your nails to clear. If ignored, it warns, the infection can spread and possibly make it hard to work or even walk.

If you have diabetes, this matters more. The APMA says people with diabetes are especially prone to fungal nails. It recommends regular checkups by a podiatrist, at least once a year.

Sources

• American Podiatric Medical Association, "Toenail Fungus"
• American Podiatric Medical Association, "Diabetes"