An ingrown toenail happens when the corner or side of your toenail curves and grows into the soft skin beside it. The earliest sign is usually tenderness along one edge of the nail, especially when you press on it or wear snug shoes. If that description matches what you’re feeling, here’s how to confirm what’s going on and gauge how serious it is.
What It Looks and Feels Like Early On
The first thing most people notice is pain along one side of the toenail, not underneath it. The skin next to the nail edge will feel tender when you touch it or bump it against something. You’ll likely see mild swelling and redness (or a darker discoloration on deeper skin tones) along that nail fold. The area may feel firm or slightly puffy compared to the same spot on your other toes.
At this early stage, you won’t see pus or broken skin. The nail itself looks normal. What’s changed is the relationship between the nail edge and the skin beside it: the nail is digging in just enough to irritate the tissue. Pain tends to be worst when you’re wearing closed-toe shoes or pressing directly on the affected side of the toe. Walking barefoot or in open sandals often brings noticeable relief.
The Three Stages of Severity
Clinicians classify ingrown toenails into three stages, and knowing where yours falls helps you decide what to do next.
Stage 1 (mild): Pain with pressure, swelling along the nail fold, and redness. The skin is irritated but intact. This is the stage most people are in when they first search for answers. Home care, like warm soaks and gently lifting the nail edge, can resolve it.
Stage 2 (moderate): The redness and swelling increase. The skin beside the nail feels warm to the touch. You may notice a small ulcer forming where the nail has broken through the skin, and the area starts producing cloudy or slightly yellowish drainage. This stage signals that infection is setting in or that the tissue damage is progressing beyond simple irritation.
Stage 3 (severe): Chronic inflammation leads to the growth of raw, bumpy tissue (called granulation tissue) that bleeds easily. The skin fold beside the nail becomes thickened and overgrown. At this point, the problem won’t resolve on its own and typically requires a minor procedure to remove part of the nail.
How to Tell If It’s Infected
Infection is the main complication to watch for. The signs overlap with a worsening ingrown nail but are more intense and progress faster. Look for skin that is noticeably warm when you touch it, increasing redness that spreads beyond the immediate nail edge, and throbbing pain that persists even when you’re not putting pressure on the toe. Pus, which can be white, yellow, or greenish, is the clearest indicator. You might also notice an unpleasant smell.
A mild ingrown nail feels hard and swollen. An infected one feels hot, and the pain shifts from “sore when pressed” to “sore all the time.” If red streaks start extending away from the toe, or if you develop a fever, the infection is spreading and needs prompt medical attention.
Why It Matters More If You Have Diabetes
People with diabetes face a specific risk. Nerve damage from diabetes can reduce feeling in the feet, which means an ingrown nail can progress to stage 2 or 3 before you feel enough pain to investigate. Reduced circulation also slows healing, so an infected ingrown toenail can quickly develop into an open wound or ulcer that is difficult to manage. In severe cases, an untreated infection can spread to surrounding tissue and, rarely, lead to the need for amputation. If you have diabetes, checking your feet daily for redness, swelling, or any changes around the nails is one of the most important habits you can build.
Conditions That Look Similar
A few other toe problems can mimic an ingrown toenail, and it’s worth knowing the differences so you don’t treat the wrong thing.
- Paronychia: This is an infection of the skin fold around the nail, often caused by bacteria entering through a hangnail or small cut. It causes redness, swelling, and pus similar to an infected ingrown nail, but the pain usually wraps around the base or sides of the nail rather than concentrating at one corner. There’s no sensation of the nail digging into the skin.
- Toenail fungus: Fungal infections cause thickening, crumbling, and white, yellow, or greenish discoloration of the nail itself. The nail may separate from the nail bed. Fungus is typically painless in the early stages, which is a key difference from an ingrown nail.
- Subungual melanoma: This rare but serious condition appears as a brown or black streak under the nail that grows wider over time. The surrounding skin may darken, and the nail can split or separate from the bed. Any dark streak under a toenail that wasn’t caused by an obvious injury, or that doesn’t grow out with the nail over several weeks, deserves evaluation.
What Causes Ingrown Toenails
Understanding the cause helps you confirm what you’re dealing with and avoid a recurrence. The most common trigger is trimming your nails too short or rounding the corners, which encourages the skin to fold over the nail edge as it grows back. Shoes that crowd the toes, particularly narrow dress shoes, heels, or cleats, push the skin against the nail and increase pressure. Stubbing your toe or dropping something on it can also change how the nail grows.
Some people are simply more prone because of their nail shape. Nails that are naturally curved or fan-shaped at the edges are more likely to dig into the surrounding skin. Adolescents and young adults are affected frequently, partly because feet are still growing and partly because of shoe choices related to sports and fashion. Sweaty feet also play a role: moisture softens the skin around the nail, making it easier for the nail edge to penetrate.
A Quick Self-Check
If you’re still unsure, try this. Sit somewhere with good lighting and rest your foot on your opposite knee. Look at the big toe first, since that’s where ingrown nails happen most often. Gently press along each side of the toenail with your fingertip. If one side is more tender, swollen, or red than the other, and if you can see the nail edge disappearing into the skin fold rather than sitting on top of it, you’re almost certainly dealing with an ingrown toenail.
Compare the affected toe to the same toe on your other foot. If one looks puffier, redder, or feels warmer, the asymmetry confirms that something is going on locally rather than being a general skin issue. Pain that worsens when you wear shoes and improves when you go barefoot is another reliable clue.