Table of ContentsView AllTable of ContentsSymptomsCausesWhen to See a ProviderComplicationsDiagnosisTreatmentPrevention
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
When to See a Provider
Complications
Diagnosis
Treatment
Prevention
A black toenail can happen because of an injury that produces a bruise called asubungual hematoma, though it can also have other causes such as a fungal infection, a vitamin deficiency, or a medical condition like diabetes or cancer.
Black toenails can be painful, but they often go away on their own. Black toenails can be treated with over-the-counter or prescription medications and, in some cases, may require treatment from a healthcare provider.
Photographer, Basak Gurbuz Derman / Getty Images
Black Toenail Symptoms
The most common symptom of black toenail is exactly that—the nail appears black, which is usually due to blood collecting underneath the nail. However, the discoloration can also be reddish, purplish, or brownish. Other toenail symptoms include:
If the area becomes infected, you may note:
What Are Common Toenail Problems and How Are They Treated?
Black Toenail Causes
There are several reasons why your toenail can become discolored. The most common include:
Bruise Under the Nail Due to Trauma or Pressure
Trauma resulting in a subungual hematoma is the most common cause of a black toenail.It may be due to stubbing the toe or dropping something on it. The injury bleeds, and the blood is trapped under the nail, where it darkens. The black toenail may fall off a few weeks after it appears and may take up to six months to grow back.
What Is Runner’s Toe?If you’re a runner or walk a lot, you may have “runner’s toe,” a form of subungual hematoma.Momentum causes your toe to bump or rub against your shoe as you move. Your feet may also swell during exercise, which can create more pressure. It often affects the second or third toe.
What Is Runner’s Toe?
If you’re a runner or walk a lot, you may have “runner’s toe,” a form of subungual hematoma.Momentum causes your toe to bump or rub against your shoe as you move. Your feet may also swell during exercise, which can create more pressure. It often affects the second or third toe.
Tight or badly fitting shoesmay rub or compress the toes and damage the nail or allow the foot to slide forward with each step and cause repetitive trauma and subungual hematoma.
Fungal Nail Infection
Thick Toenails: Treatments for Each Cause
Ingrown Toenail
With an ingrown toenail,your toenail is growing into the skin surrounding the nail bed. It may lead to bacterial infection, which can discolor the nail.
Underlying Health Condition
Health conditions that affect circulation like diabetes and kidney disease, heart infection, psoriasis, oranemiacan cause discolored toenails.In people with diabetes, discolored toenails tend to be more of a yellowish hue, though blackening can occur in some cases.
In some cases, certain deficiencies can cause black toenail. Avitamin B12 deficiencycan lead to black toenails. Fortunately, the discoloration is reversible.
Melanoma
Rarely, black toenail is due tomelanoma. When it does happen, it usually appears as a dark streak. Subungual melanoma is a particular type of skin cancer, and while rare, can be very serious if left untreated.
Melanoma: Signs and Symptoms
Medications
There are medications that can lead to toenail discoloration due to effects on the nail bed, blood supply to the nail, or increased sensitivity to light. These include:
When to See a Healthcare Provider
If you know you injured your toenail, it is not painful, and less than half of the toenail is black, you don’t need to go to a healthcare provider. But contact a healthcare provider if any of these apply:
If you have spreading discoloration outside the nail or bumps under the nail, it’s important to call a healthcare provider so they can examine you for infection or, in rare cases, skin cancer that needs prompt treatment.
You can also see a dermatologist for a black toenail, especially if you suspect melanoma.
Complications from a black toenail can include permanent damage to the nail, in which it grows back misshapen or thickened.
Toenail fungus can spread to other toes if it isn’t treated. If the discoloration is due to melanoma, it may spread elsewhere in the body.
How Are Black Toenails Diagnosed?
A healthcare provider can examine your toenail and will ask you about any recent injury, activities, and style of footwear. Depending on the symptoms, they may ask for tests for underlying conditions that can lead to a black toenail.
If they suspect a fungal infection, they can take a small sample of nail clippings and send them to a lab for analysis in order to determine the recommended treatment option.
What Does Toenail Fungus Look Like When It’s Dying?
How Do You Treat a Toenail That Has Turned Black?
If the black toenail is not causing you pain and less than half of the nail is black, there is no need to treat it. Over time, the nail will grow out and the discoloration will no longer be present. See a healthcare provider for evaluation if more than half of the nail is black due to trauma so they can check for a subungual laceration (a tear or cut).
If it’s painful due to swelling or pressure, you can try home treatments, including:
If the discoloration covers more than half the nail, if the nail is beginning to separate, or if the injury is severe, your healthcare provider may recommend removing the nail.They will numb the area first so that the procedure isn’t painful.
Topical prescription medications that you apply to the nail include:
Oral prescription medications include:
You may have to use more than one medication, and it may take months or even more than a year to cure the infection as the toenail grows.The nail may grow back differently.
If you have another kind of infection, from bacteria or yeast, your healthcare provider can prescribe appropriate treatment, including antibiotic ointments or oral medication if necessary.
In the rare case of subungual melanoma, the treatment is usually surgical removal of the growth. If it has spread beyond the nail or toe, your healthcare provider will discuss treatment options with you.
How to Find the Toenail Fungus Treatment That Will Work for You
Summary
A black toenail is often the result of trauma to the nail in which the injury bleeds and the blood pools under the nail. It should resolve on its own as the nail grows out.
There are other causes for a black toenail, including fungal infections, ingrown toenails, and vitamin B12 deficiency. Some medications and, rarely, cancer, can also cause a black toenail.
If the nail hurts after injury, a healthcare provider can drain the blood painlessly. For infections, antifungals and antibiotics that you apply to the nail or take orally can help. If a black toenail hurts, the discoloration has appeared gradually, or the discoloration spreads beyond the nail, call a healthcare provider.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Splinter hemorrhages.Piao C, Aronowitz PB.Beau’s toes.J Gen Intern Med. 2020;35(8):2467-2467. doi:10.1007/s11606-020-05883-2Lee DK, Lipner SR.Optimal diagnosis and management of common nail disorders.Ann Med.2022;54(1):694-712. doi:10.1080/07853890.2022.2044511American College of Foot and Ankle Surgeons.Black toenails.Singal A, Bisherwal K.Melanonychia: etiology, diagnosis, and treatment.Indian Dermatol Online J. 2020;11(1):1-11. doi:10.4103/idoj.IDOJ_167_19American Academy of Dermatology Association.How to check your nails for melanoma.Zhang S, Liu X, Cai L, Zhang J, Zhou C.Longitudinal melanonychia and subungual hemorrhage in a patient with systemic lupus erythematosus treated with hydroxychloroquine.Lupus. 2019;28(1):129-132. doi:10.1177/09612033188126American Academy of Dermatology Association.Nail fungus: diagnosis and treatment.MedlinePlus.Nail injuries.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Splinter hemorrhages.Piao C, Aronowitz PB.Beau’s toes.J Gen Intern Med. 2020;35(8):2467-2467. doi:10.1007/s11606-020-05883-2Lee DK, Lipner SR.Optimal diagnosis and management of common nail disorders.Ann Med.2022;54(1):694-712. doi:10.1080/07853890.2022.2044511American College of Foot and Ankle Surgeons.Black toenails.Singal A, Bisherwal K.Melanonychia: etiology, diagnosis, and treatment.Indian Dermatol Online J. 2020;11(1):1-11. doi:10.4103/idoj.IDOJ_167_19American Academy of Dermatology Association.How to check your nails for melanoma.Zhang S, Liu X, Cai L, Zhang J, Zhou C.Longitudinal melanonychia and subungual hemorrhage in a patient with systemic lupus erythematosus treated with hydroxychloroquine.Lupus. 2019;28(1):129-132. doi:10.1177/09612033188126American Academy of Dermatology Association.Nail fungus: diagnosis and treatment.MedlinePlus.Nail injuries.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
MedlinePlus.Splinter hemorrhages.Piao C, Aronowitz PB.Beau’s toes.J Gen Intern Med. 2020;35(8):2467-2467. doi:10.1007/s11606-020-05883-2Lee DK, Lipner SR.Optimal diagnosis and management of common nail disorders.Ann Med.2022;54(1):694-712. doi:10.1080/07853890.2022.2044511American College of Foot and Ankle Surgeons.Black toenails.Singal A, Bisherwal K.Melanonychia: etiology, diagnosis, and treatment.Indian Dermatol Online J. 2020;11(1):1-11. doi:10.4103/idoj.IDOJ_167_19American Academy of Dermatology Association.How to check your nails for melanoma.Zhang S, Liu X, Cai L, Zhang J, Zhou C.Longitudinal melanonychia and subungual hemorrhage in a patient with systemic lupus erythematosus treated with hydroxychloroquine.Lupus. 2019;28(1):129-132. doi:10.1177/09612033188126American Academy of Dermatology Association.Nail fungus: diagnosis and treatment.MedlinePlus.Nail injuries.
MedlinePlus.Splinter hemorrhages.
Piao C, Aronowitz PB.Beau’s toes.J Gen Intern Med. 2020;35(8):2467-2467. doi:10.1007/s11606-020-05883-2
Lee DK, Lipner SR.Optimal diagnosis and management of common nail disorders.Ann Med.2022;54(1):694-712. doi:10.1080/07853890.2022.2044511
American College of Foot and Ankle Surgeons.Black toenails.
Singal A, Bisherwal K.Melanonychia: etiology, diagnosis, and treatment.Indian Dermatol Online J. 2020;11(1):1-11. doi:10.4103/idoj.IDOJ_167_19
American Academy of Dermatology Association.How to check your nails for melanoma.
Zhang S, Liu X, Cai L, Zhang J, Zhou C.Longitudinal melanonychia and subungual hemorrhage in a patient with systemic lupus erythematosus treated with hydroxychloroquine.Lupus. 2019;28(1):129-132. doi:10.1177/09612033188126
American Academy of Dermatology Association.Nail fungus: diagnosis and treatment.
MedlinePlus.Nail injuries.
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
