An ingrown toenail happens when the corner or side of a nail grows into the soft skin next to it, and the earliest sign is usually a focused tenderness along one edge of the nail that wasn’t there before. It almost always affects the big toe, and the symptoms follow a fairly predictable pattern that makes it straightforward to identify at home.
What It Looks and Feels Like
The first thing most people notice is pain and tenderness along the side of the toenail, especially when pressing on it or when a shoe pushes against the toe. At this early stage, the skin beside the nail may look slightly pink or puffy compared to the other side. You might only feel it when you’re wearing shoes or walking, not when your foot is bare and at rest.
As the nail digs further into the skin fold, the swelling becomes more obvious. The skin along the affected edge turns red and feels firm and warm to the touch. Pressing gently on the side of the nail will reproduce a sharp, localized pain, which is a reliable way to confirm what’s going on. If the opposite edge of the same nail doesn’t hurt when you press it the same way, that contrast is a strong clue.
You can also look closely at the nail itself. Pull the skin gently away from the nail edge and see if the corner of the nail appears to be curving downward into the skin rather than growing straight out. Sometimes the skin has already started to grow over the nail edge, making it hard to see where the nail ends.
Signs the Nail Is Infected
Not every ingrown toenail gets infected, but the longer it goes untreated, the higher the chance. An infection changes the picture noticeably. The surrounding skin turns a deeper pink or red and may feel hot. You might see a red, moist bump forming where the skin overlaps the nail edge, and the area can start releasing a yellowish or whitish discharge. Some people notice a foul smell.
Pain at this stage is typically constant, not just when pressure is applied. You may find it difficult to wear any closed-toe shoe comfortably. If red streaks start spreading away from the toe, or if you develop a fever, the infection has moved beyond the local area and needs prompt attention.
Common Causes to Consider
Thinking about what might have triggered the problem can help you confirm your suspicion. The most common cause is trimming the nail incorrectly. If you recently cut your toenails in a rounded or tapered shape, the way you might trim fingernails, that creates a nail edge that curves downward and digs into the skin as it grows out. The nail essentially scrolls inward at its edges. Cutting straight across prevents this.
Footwear is the other big factor. Shoes that are too tight compress the toes and push skin against the nail edge, especially during activities like running or jumping where your foot shifts forward inside the shoe. Shoes that are too loose cause a similar problem because the foot slides around, creating repetitive friction on the big toe. If you recently started wearing new shoes, increased your activity level, or spent long hours on your feet, any of these could explain a sudden ingrown nail.
Other triggers include stubbing the toe, dropping something on it, or having naturally curved nails that run in your family. Sweaty feet can soften the skin enough that the nail pushes into it more easily.
How to Check at Home
A simple self-exam takes about a minute. Sit somewhere with good lighting and rest your foot on your opposite knee so you can see the toe clearly. Look at both sides of the big toenail. Compare them to each other and to the same nail on your other foot. You’re looking for asymmetry: one side that’s redder, puffier, or more tender than the other.
Gently press the skin along each side of the nail with a fingertip. A normal nail won’t hurt when you do this. An ingrown nail will produce a sharp, specific pain right where the nail meets the skin fold. Try to see if the nail edge is visible or if skin has started to cover it. If you can’t see the corner of the nail on one side but can on the other, that buried corner is likely the culprit.
If the area is draining fluid, gently blot it with a clean tissue and note the color. Clear or slightly yellowish fluid suggests mild irritation. Thick, opaque pus or a greenish tint points toward infection.
When It Needs Professional Care
A mild ingrown toenail, one that’s tender and slightly red but not infected, often responds to home care: soaking the foot in warm water a few times a day, wearing open-toed shoes, and letting the nail grow out past the skin edge. But if you see signs of infection (pus, increasing redness, worsening pain), the situation typically requires a provider to trim or remove the ingrown portion of the nail. This is a quick in-office procedure done under local numbing.
People with diabetes face a higher risk of complications from any foot wound, including ingrown toenails. Reduced blood flow and nerve sensation in the feet mean an infection can progress quickly without you feeling the full extent of it. If you have diabetes, skip home treatment entirely and have a podiatrist manage the nail from the start.
The same applies if you have peripheral artery disease, neuropathy from any cause, or a weakened immune system. For everyone else, a good rule of thumb is that if home soaking hasn’t improved the symptoms within three to five days, or if the pain is getting worse rather than better, it’s time for a professional to take a look. Diagnosis is straightforward: a provider can confirm it with a visual exam of the nail and surrounding skin, no imaging or lab tests needed.