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HealthInfo Canterbury

Ingrown toenail

An ingrown toenail (onychocryptosis) happens when part of your nail pierces the skin. This can often lead to infection.

How bad an ingrown toenail is can vary. Usually, the side of the nail penetrates (curves down) and it is difficult to see the edge of the nail. In some cases, the corner or a small spike of nail can penetrate the skin, which can result in an infection.

If an ingrown toenail is infected the toe will be red, inflamed, and painful.

Causes of ingrown toenails

Lots of things can cause ingrown toenails:

Poor nail trimming (a very common cause)

Trimming or tearing down the sides of your toenail can cause an ingrown toenail. Leaving a sharp corner also puts pressure on the skin.

The shape of the nail

If you have a curved nail it is more likely to become an ingrown toenail than a flat one. The shape of the nail is usually inherited, but it can be influenced by trauma or shoe pressure.

Shoe pressure

Tight footwear is more likely to increase pressure between the skin in the nail fold and nail.


Injury can change the shape of the nail.

Toe pressure

Pressure from the toe next to the nail that is ingrown can be a cause.

A plump toe

If you have a plump toe or your feet swell, you are more prone to ingrown toenails.

Symptoms of an ingrown toenail

Pain is the main symptom of an ingrown toenail. It usually starts as minor discomfort and increases to pain.

Your toe isn't necessarily infected, but this can develop after the nail breaks the skin to become ingrown. The infection can spread, making the toe red and inflamed (paronychia). Pus may also develop and large growths of skin can develop if the ingrown toenail is left for too long.


If your toe is swollen or painful, the redness has spread beyond your toe and into your foot, or you are feeling unwell, you will need urgent medical attention for Cellulitis.

Preventing an ingrown toenail

Take the following steps to prevent ingrown toenails:

Other advice:

Getting help for an ingrown toenail

A podiatrist can help with an infected nail and, in many cases, can remove an ingrown toenail without surgery or too much pain. If needed, they will recommend minor surgery and, in some circumstances, refer you to your GP for medication. Many GPs can also help with infected nails and ingrown toenails.

If you have diabetes, it is important to get any foot problems treated quickly as sometimes seemingly minor things can progress to cause serious problems. If you have diabetes and there is any sign of infection (increasing redness, swelling, pus, pain, or feeling unwell), seek medical attention urgently. If your doctor refers you to a podiatrist because you have diabetes, podiatry treatment could be publicly funded.

Written by Podiatry NZ. Adapted by HealthInfo clinical advisers. Last reviewed September 2019.


Page reference: 273523

Review key: HICCA-28239