Ingrown Toenails: Why They Hurt and How to Fix Them

It starts small. Your big toe feels tender in a shoe, then sore when you walk, then throbbing even at rest. Look closely and you will often find the culprit: the corner of the toenail has grown into the soft skin beside it.

Ingrown toenails are one of the most common foot complaints in the United States, and one of the most misunderstood. People often blame bad luck, when in most cases the cause is a habit they repeat every week: how they cut their nails, or the shoes they squeeze their feet into. Most mild cases improve with simple home care, and stubborn ones have a quick fix at a podiatrist's office. The key is knowing which stage you are in, and not letting a small problem become infected.

What exactly is an ingrown toenail?

A toenail is supposed to grow straight out, with its edges resting on top of the skin. An ingrown toenail, called onychocryptosis by doctors, happens when the edge of the nail grows down into the surrounding skin instead. The skin responds as it would to any foreign object: it gets red, swollen, and tender, and if bacteria get in, infected.

Big toes account for the large majority of cases, simply because they carry the most pressure and have the largest nails. It is more common in teenagers, whose nails grow faster, and in older adults, whose nails thicken and curve with age. People with diabetes, poor circulation, or nerve damage in the feet face higher stakes, because even a minor toe infection can escalate quickly for them.

The three causes behind most cases

Cutting your nails too short or rounding the corners

This is the number one cause, and it is entirely preventable. When you cut the corners into a rounded shape, or trim the nail shorter than the tip of the toe, the skin folds over the edge as the nail grows back, and the new nail has nowhere to go but into that skin.

Fingernails can be rounded safely. Toenails should not be. The correct shape is straight across, with the corners left visible and just long enough to clear the skin at the tip of the toe.

Shoes that squeeze your toes

Tight dress shoes, pointed boots, and athletic shoes a half-size too small all push the skin of the toe up against the nail edge, hour after hour. High heels add to the problem by forcing weight forward onto the toes.

Injury and pressure

Stubbing a toe, dropping something heavy on your foot, or playing a sport with repeated toe impact can bend a nail so it grows back unevenly. Some people are also born with nails that curve sharply downward at the edges, which makes them prone to the problem no matter how carefully they trim.

How to tell if it is infected

A mild ingrown toenail is painful but not dangerous: redness and tenderness along one edge, mild swelling, and pain when pressure is applied. An infection adds warning signs that should not be ignored:

• Increasing pain, warmth, or swelling that spreads beyond the nail edge
• Pus or cloudy fluid draining from the side of the nail
• Red streaks running from the toe toward the foot
• A fever, or a bad smell coming from the toe
• Overgrown, bleeding tissue (called granulation tissue) bulging beside the nail

If you have diabetes, poor circulation, or a weakened immune system, do not treat even a mild ingrown toenail at home. See a clinician promptly.

What helps at home for a mild case

For a tender toe without signs of infection, home care over a few days often turns things around.

Soak and lift, gently

Soak the foot in warm water for 15 to 20 minutes, two or three times a day. After soaking, dry the foot thoroughly. Some podiatrists suggest gently lifting the nail edge with a small piece of clean cotton tucked underneath it, changed daily, to guide the nail over the skin rather than into it. Be gentle: forcing the nail usually makes things worse.

Keep it clean and cushioned

Wash the toe daily with soap and water, and apply a thin layer of antibiotic ointment if the skin is broken. Wear open-toed shoes or sandals when you can, and choose shoes with a wide toe box that does not press on the sore edge.

Do not perform bathroom surgery

The most common mistake is trying to cut out the ingrown corner yourself. Cutting a V-shaped notch in the middle of the nail, a popular folk remedy, does nothing, and digging at the corner with sharp instruments risks tearing the skin and driving bacteria deeper.

Over-the-counter pain relief, such as acetaminophen or ibuprofen taken as directed, can help while the toe heals. If pain is not clearly improving within three to four days, or if any infection signs appear, it is time for professional help.

When to see a podiatrist, and what they do

A podiatrist visit for an ingrown toenail is usually quick, and for recurring cases it can be permanently curative.

For a one-time ingrown nail, the doctor numbs the toe, then removes the narrow strip of nail that is digging in, a procedure called a partial nail avulsion. Relief is often immediate, and most people return to normal shoes within a few days.

For nails that keep coming back, the doctor may also treat the small section of nail root under that edge, usually with a chemical such as phenol, so that edge does not grow back. The nail still looks essentially normal afterward, just slightly narrower. Antibiotics are prescribed only when there is an infection.

How to keep it from coming back

First, cut toenails straight across, not rounded, and leave them long enough that the corners sit just past the skin at the tip of the toe. Cut after a shower or soak, when nails are softer, and use clean, sharp nail clippers made for toes rather than small fingernail clippers. If your nails are thick or hard to cut, a podiatrist can trim them safely.

Second, wear shoes that fit. There should be about a half-inch, roughly a thumb's width, between your longest toe and the end of the shoe, and the toe box should be wide enough that your toes can wiggle without pressing together. Replace athletic shoes when they start to pinch, and save narrow or pointed shoes for short occasions rather than all-day wear.

Keep feet clean and dry as well: wash daily, dry carefully between the toes, and treat athlete's foot promptly, since fungal infections can thicken and distort nails.

The bottom line

An ingrown toenail hurts far out of proportion to its size, but it is rarely a mystery: nails cut too short or rounded, shoes that crowd the toes, or a past injury. Mild cases often settle with warm soaks and roomier shoes, while infected or recurring nails deserve a quick podiatrist visit rather than a home operation with clippers. Treat the sore toe early, cut your nails straight across, and give your toes real room in your shoes.