Black Spots on Toenails: Causes and Concerns

Nail problems

Hello Dr.
Hong, I have noticed a small black spot on the side of my left big toe, close to the nail, but not on the nail bed.
It is about 0.1 millimeters in size and is neither painful nor itchy.
Could this be related to a skin condition? Thank you, doctor.

Juzi, 20~29 year old female. Ask Date: 2021/09/11

Dr. Hong Yuanbin reply Internal Medicine

Hello, based on your description, it seems there may be a foreign body lodged in the nail fold or localized bleeding.
If it gradually resolves on its own, there is no need for concern.
However, if it continues to expand or if you experience pain, you should seek medical attention from a dermatologist.
Thank you for your inquiry.

Reply Date: 2021/09/11

More Info

Hello! Thank you for your question regarding the black spot on your toenail. It’s understandable to be concerned about any changes in your nails, as they can sometimes indicate underlying health issues.
The presence of a black spot on your toenail can have several potential causes. One of the most common reasons for a dark spot under the nail is a subungual hematoma, which occurs when there is bleeding underneath the nail due to trauma or injury. This can happen even if you don’t remember injuring your toe, as sometimes minor trauma can go unnoticed. The blood collects and can appear as a dark spot, and while it may not be painful, it can sometimes cause discomfort if the pressure builds up.

Another possibility is a fungal infection, which can lead to discoloration of the nail. Fungal infections often cause nails to become thickened, discolored, and sometimes brittle. However, these infections usually come with additional symptoms such as itching or a foul smell, which you mentioned you do not have.

In some cases, a black spot on the toenail can be a sign of a more serious condition, such as melanoma, a type of skin cancer that can occur under the nail. While this is less common, it is important to monitor any changes in the size, shape, or color of the spot. If the spot grows, changes in appearance, or if you develop any other symptoms, it would be prudent to seek medical evaluation.

You also mentioned that the spot is located near the edge of the nail and is about 0.1 millimeters in size. If it remains stable and does not change over time, it may not be a cause for immediate concern. However, it is always best to err on the side of caution. If you have any doubts or if the spot begins to change, I recommend consulting a healthcare professional, preferably a dermatologist or a podiatrist, who can examine the area more closely and may perform a biopsy if necessary to rule out any serious conditions.

In summary, while the black spot on your toenail could be due to a benign cause such as a bruise or a fungal infection, it is essential to keep an eye on it. If you notice any changes or if you have any accompanying symptoms, please seek medical advice. Regular check-ups and being aware of changes in your body are key to maintaining good health. Thank you for reaching out, and I hope this information helps you!

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