Ingrown toenails happen when the edge of the nail pushes into the surrounding skin, triggering a foreign body reaction that causes pain, swelling, and sometimes infection. The good news: most cases are caused by a handful of preventable habits, and changing them can keep the problem from starting in the first place.
Why Toenails Grow Inward
The nail itself is made of hard keratin, and it sits in a groove of softer skin on each side. When the nail edge slips sideways into that skin, your body treats the nail like a splinter and launches an inflammatory response. Two things make this happen most often: cutting the nail too short, which frees the edge to slide sideways into the skin, and external pressure from tight shoes, which compresses the skin against the nail and essentially turns the nail into a cutting surface.
Some people are also genetically predisposed. A nail shape called a pincer nail, where the nail curves excessively from side to side, runs in families with what appears to be an autosomal dominant inheritance pattern. If your parents or grandparents dealt with chronic ingrown nails, you may need to be more vigilant about prevention than the average person. Adolescents and athletes also tend to be at higher risk.
How to Cut Your Toenails Correctly
This is the single most impactful thing you can do. The American Academy of Dermatology recommends cutting straight across when trimming toenails. Resist the urge to round the corners or follow the curve of your toe. When you cut into the corners, you remove the nail material that normally guides growth over the top of the skin, and the remaining edge can dig inward as it grows out.
Leave a bit of white nail visible at the tip. Cutting too short removes the constraint that keeps the nail tracking forward, letting the edges slip sideways into the nail groove. After trimming, use an emery board to file down any sharp edges that could catch on skin or socks. If you use toenail clippers, choose a straight-edged pair rather than curved ones designed for fingernails.
Choosing the Right Shoes
A toe box that’s too narrow is one of the most common mechanical triggers. Tight shoes press the skin folds against the nail edge for hours at a time, and that sustained pressure can force the nail into the flesh. Look for shoes with a wide toe box that lets you wiggle your toes freely. When you’re standing, there should be roughly a thumb’s width of space between your longest toe and the end of the shoe.
This matters even more if you’re active. Runners, soccer players, and hikers spend long stretches with their toes jammed against the front of their shoes, especially on downhill terrain. Giving your toes time outside closed shoes helps too. Going barefoot at home or switching to open-toed sandals on rest days lets the nail grow without any lateral compression.
What to Tell Your Pedicurist
Salon pedicures are a common, overlooked cause of ingrown nails. When a nail technician rounds the corners or digs into the sides of the nail to clean them out, it disrupts the nail’s natural growth path. The nail then grows into the surrounding skin instead of over it.
Before your pedicure starts, ask the technician to trim your nails straight across without rounding or cutting into the corners. This is a reasonable, routine request, and any reputable technician will comply. If you’ve had ingrown nails before, it’s worth being direct about it so they know to be especially careful.
The Dental Floss Trick for Early Ingrowns
If you notice the earliest signs of an ingrown nail (mild tenderness along the edge, slight redness) you can sometimes redirect the nail before it becomes a real problem. Pull a short piece of dental floss under the nail edge where it’s pressing into the skin, then snip off the ends, leaving a small piece tucked underneath. This lifts the nail just enough to encourage it to grow over the skin rather than into it. Inserting two or three small pieces works even better and is generally less painful than the older method of wedging cotton under the nail.
This only works for very early, mild cases. If you already have significant swelling, pus, or intense pain, the nail has progressed past the point where home remedies are effective.
Extra Precautions for People With Diabetes
Diabetes narrows and hardens blood vessels, which reduces circulation to the feet. Poor circulation makes it harder for your body to fight infection and heal wounds. Because of this, even a minor ingrown nail can escalate into a serious infection that threatens the toe or foot.
If you have diabetes, trim your toenails straight across and file sharp edges with an emery board. Wash your feet daily in warm (not hot) soapy water, dry them carefully, and apply moisturizer everywhere except between the toes, where trapped moisture can invite infection. Check your feet every day for redness, sores, or any changes around the nails. Wear sturdy, well-fitting shoes at all times, including indoors, to reduce the risk of accidental injury. And if you notice numbness, a sore that isn’t healing, or signs of infection around a nail, contact your doctor promptly. What would be a minor nuisance for most people can become a much bigger problem when circulation is compromised.
When Prevention Isn’t Enough
Some people do everything right and still get ingrown nails, particularly those with inherited nail curvature. When an ingrown toenail reaches the stage of persistent pain, swelling, or infection, conservative measures like soaking and floss tend to fail, and a minor surgical procedure becomes the most reliable option.
Not all procedures are equal. Simply cutting out the ingrown edge of the nail has a recurrence rate of about 39%, and removing the entire nail is even worse, with recurrence as high as 83%. The most effective approach is a partial removal of the nail combined with a chemical treatment (phenol) to the nail root, which prevents that strip of nail from growing back. In one study published in the Annals of Family Medicine, this technique had a 99.7% success rate over two years with only a single recurrence out of hundreds of cases. Recovery is relatively quick, and because only a narrow strip of nail is permanently removed, the cosmetic result is usually subtle.
If you’ve had more than one or two ingrown nails on the same toe despite good trimming habits and proper shoes, this kind of procedure can break the cycle for good.