Could Your Curled Toenail Indicate an Infection?

Curled toenails are toenails that curve inward against the natural shape of your nail. They can cause symptoms such as pain, discomfort, and discoloration, among others. Everything from improper footwear to fungal infections can cause your toenails to curve. Typically, curled toenails form gradually and happen on your big toe.

Curled toenails can take many different forms. For example, spoon nails are indented and curved towards the center, while pincer nails curl away from the center and deeper into the folds of your nail. Ingrown toenails grow into your toe on the sides, while onychogryphosis, also known as ram’s horn, happens when your toenails twist outward and thicken.

If left untreated, curled toenails can lead to infection or other health complications. It’s important to keep track of your symptoms to know when to seek help from a healthcare provider or podiatrist (a doctor specializing in foot conditions).

In a healthy toenail, your nail plate—the hardened, translucent shell on top of your nail bed (the tissue at the base of your nail), is smooth and flat. A nail is curled when the nail plate curves instead, potentially digging into the skin around the nail. Curled toenails affect the tissue that forms your nails, which can cause mild to severe pain.

Symptoms of a curled toenail may include:

Thick nails with a bumpy or rough texture
Discoloration of your toenail plate
White or brown buildup under your nail plate
Separation of the nail plate from the nail bed or matrix
Brittle or crumbling toenails
Pain
Swelling around the nail
Bleeding or discharge
Foul or cheese-like odor (a symptom of toenail fungus)

Ingrown nails (onychocryptosis) and toenail fungus (onychomycosis) are the most common causes of curled toenails. Viral infections and other preexisting conditions can cause additional types of nail growth away from your nail bed. Toenails that are not properly trimmed or constantly squeezed into shoes that are too tight can also cause toenail complications.

Ingrown Toenail Symptoms

Ingrown toenails are a relatively common condition affecting 2.5-5% of the United States population. This condition causes toenails to curl or grow into a corner or side of the surrounding skin, also known as a lateral nail fold. This can cause your nails to thicken and change in color and growth.

Common symptoms—most often affecting your big toe—include pain and swelling in the nail fold (the skin that surrounds your nail). Pain may go away on its own over time, especially with proper nail care.

More severe cases occur when you have a bacterial or viral infection while developing an ingrown nail. Bacterial infections are potential causes of paronychia, which causes severe redness, swelling, or pus to leak from your nail.  

Fungal Infection Symptoms 

The fungus from a fungal infection in your toenail can live in the dead tissue of your nail. Therefore, the longer you take to treat a fungal infection, the longer it may take to get rid of the fungus, as the fungus has more time to spread among affected tissue.

Symptoms of toenail fungus include:

Thickened toenails that may start to separate from your nail bed Brittle, crumbling or cracking nails White or yellow streaks underneath the nail plateCurling or bending of your nailYellow, green, or brown pus buildup underneath your nailDull or brown appearance on your nail

Pincer Toenail Symptoms 

A pincer toenail is a type of ingrown nail that occurs when toenails thicken and form C-shaped curves as the center of your nail pushes upward and further from your nail bed. As your nail edge starts to dig into your nail bed, you may feel more pain around your toenail.

There are two main types of pincer toenails—a tile-shaped nail and a plicated nail. A tile-shaped pincer nail is when both sides are ingrown, whereas a plicated nail only affects one side.

Pincer toenails can cause swelling and symptoms of infection, such as a feeling of warmth around the nail and leaking fluid. 

Onychogryphosis Symptoms 

Also known as ram’s horn nails, onychogryphosis causes toenails to thicken and grow outward. Over time, the nail forms an oyster-like or twisted horn shape. Certain skin conditions can also make you more likely to develop onychogryphosis as you age. Psoriasis is one of a few skin conditions that can increase your likelihood of developing onychogryphosis.

Your nails may also appear discolored and turn yellow, brown, or green as they become thicker. This is most often seen in the big toenails of people older than 75. Onychogryphosis can also come from having hygienic concerns with your feet.

Onychauxis Symptoms 

Onychauxis is a nail condition that can be either genetic or caused by aging. It causes toenails to grow thicker, separate from the nail bed, and curl. It is more prevalent in people over the age of 75. This condition can also cause toenails to turn yellow, white, red, or black. Pain and bleeding can also occur.

Spoon Nails Symptoms 

Spoon nail, or koilonychia, is a rare nail condition where the middle of your toenails bend inward. Spoon nails are typically more brittle and thin than ingrown nails.

This condition can be genetically passed on or a symptom of several conditions, including iron deficiency anemia (not having enough iron in your blood), psoriasis (an autoimmune skin condition), psoriatic arthritis (a chronic inflammatory condition), and cancer.

A curled toenail can be contagious, depending on its cause. You can contract a fungal infection from someone through skin-to-skin contact. However, it is unlikely your toenail will curve in response to a fungal infection alone. If a curled toenail is caused by injury or improper footwear, it won’t be contagious.

To prevent a fungal infection, practice good hygiene in shared spaces like gyms, swimming pools, and saunas. Avoid sharing towels or nail clippers with other people.

Curled toenails can be uncomfortable and painful. They can also be a sign of a skin condition. Reach out to your healthcare provider or a podiatrist (a doctor specializing in conditions affecting your feet) if you notice concerning changes in your toenail, especially if you have a pre-existing condition like diabetes or nerve damage. A dermatologist (a doctor specializing in hair, skin, and nails) can also check for skin conditions on your foot.

While emergency care is rarely needed for a change in the appearance of your toenails, seek immediate care if you notice red streaks along your toes or a change in nail color. This may be a sign of a more severe infection, such as sepsis (a potentially life-threatening condition caused by an extreme reaction to infection).

Several conditions can cause curled toenails, along with changes in color, thickness, and texture. Ingrown nails grow into the surrounding skin, toenail fungus pushes the nail up and away from the toe, and other conditions cause the nail to grow away from the nail bed. 

Depending on the cause, additional symptoms may include pain, swelling, and redness. In some cases, these conditions can lead to infection. See a healthcare provider if your symptoms are concerning you or if you are experiencing pain that doesn’t go away with at-home care.