An infected toenail typically shows discoloration, thickening, and changes in texture or shape. The exact appearance depends on whether the infection is fungal, bacterial, or caused by an ingrown nail, and each type looks noticeably different. Roughly 5.5% of U.S. adults deal with fungal toenail infections alone, making this one of the most common nail problems people encounter.
Fungal Infections: The Most Common Type
Fungal toenail infections usually start as a white or yellow-brown spot under the tip of the nail. In the earliest stage, you might notice only slight discoloration and a subtle lift where the nail separates from the skin beneath it. The nail may feel a little thicker than usual, but the changes are easy to dismiss or overlook entirely.
As the fungus works deeper into the nail over the following weeks and months, the appearance becomes harder to ignore. The nail thickens noticeably, turns a deeper yellow or brown, and begins to crumble or look ragged along the edges. The surface can develop a rippled or puckered texture, and the nail may become misshapen. In more advanced cases, large sections of the nail separate from the nail bed underneath, and the nail may give off a mild odor.
At the chronic stage, which can develop after a year or more without treatment, the nail may detach almost completely. The damage can become severe enough to cause pain when walking, and the infection often spreads to neighboring toenails. At this point, the nail is less likely to regrow normally even after treatment.
How Fungal Infections Progress Over Time
Fungal toenail infections move slowly compared to bacterial ones. The early stage lasts about four to six weeks, during which the only visible sign may be a small discolored patch. By two to three months, the infection reaches a moderate stage with more obvious thickening and color change. After six months, the structural damage becomes significant: crumbling edges, major separation from the nail bed, and sometimes pain. Infections that persist beyond a year enter a chronic phase where permanent nail damage is more likely.
This slow timeline is part of why people often delay treatment. The early signs look cosmetic rather than medical, and it’s easy to assume the nail will improve on its own. It won’t. Fungal infections don’t resolve without treatment, and the longer they persist, the harder they are to clear.
Bacterial Infections Look Different
Bacterial toenail infections produce a distinctly different set of symptoms. Instead of the slow discoloration of a fungal infection, bacterial infections cause redness, swelling, and warmth around the nail. The skin near the nail looks puffy and inflamed, and touching it causes real pain. You may see pus draining from the edges of the nail or notice open sores and blisters forming nearby. The area often has an unusual smell that’s different from the mild odor of a fungal infection.
Bacterial infections tend to develop faster and feel more urgent. While a fungal infection builds over weeks and months, a bacterial infection can become noticeably painful within days. The affected toe may swell enough that your shoe feels tight on that foot. Bacterial infections are less common on the feet than fungal ones, but they carry a higher risk of spreading beyond the toe if untreated. Severe cases can cause fever, chills, and nausea as the infection moves into surrounding tissue.
Ingrown Toenails With Infection
An ingrown toenail becomes infected when the nail edge digs into the surrounding skin and bacteria enter the break. The hallmark appearance is a red, swollen border along one or both sides of the nail, with skin that looks tight and shiny from inflammation. Pus may collect along the nail edge, appearing as a white or yellowish pocket. The skin around the nail can develop a raw, granular texture where the tissue is trying to heal around the embedded nail.
Infected ingrown toenails are usually painful enough that you notice them quickly. Pressure from socks or shoes makes the discomfort worse, and even light contact with a bedsheet can be uncomfortable. The big toe is the most common location.
Warning Signs of a Spreading Infection
Most toenail infections stay localized, but certain visual changes signal that the infection is moving into deeper tissue. Watch for redness that extends beyond the immediate area around the nail and spreads up the toe or onto the foot. Skin that feels hot to the touch, looks dimpled, or develops blisters in a widening pattern suggests cellulitis, a potentially serious skin infection that can spread rapidly through the body.
Red streaks moving away from the toe toward the ankle are a particularly urgent sign. Fever or chills alongside a swollen, painful toe mean the infection is no longer just a nail problem. People with diabetes or conditions that reduce blood flow to the feet face higher risk of these complications, because reduced circulation makes it harder for the immune system to contain infections in the toes.
Fungal vs. Bacterial: A Quick Comparison
- Speed of onset: Fungal infections develop over weeks to months. Bacterial infections can become serious within days.
- Color changes: Fungal infections turn nails yellow, brown, or white. Bacterial infections make surrounding skin red and inflamed.
- Pain: Fungal infections are often painless until advanced stages. Bacterial infections hurt early.
- Drainage: Fungal infections rarely produce discharge. Bacterial infections frequently produce pus or clear fluid.
- Texture: Fungal infections cause thickening, crumbling, and flaking. Bacterial infections cause swelling, blistering, and skin breakdown.
- Risk level: Fungal infections are persistent but rarely dangerous in otherwise healthy people. Bacterial infections can become systemic.
Getting a Diagnosis
Visual appearance alone isn’t always enough to confirm the type of infection, because some bacterial infections mimic the look of fungal ones. A podiatrist or dermatologist can take a small clipping of the affected nail and send it for lab testing to identify the specific organism causing the problem. This matters because antifungal and antibacterial treatments are completely different, and using the wrong one wastes time while the infection advances.
Treatment options range from topical medications applied directly to the nail to oral medications for more stubborn infections. In some cases, the damaged portion of the nail is removed to let medication reach the infection more effectively and to allow healthy nail to grow in. Fungal toenails grow out slowly, so even with successful treatment, it can take six to twelve months before the nail looks fully normal again.