Black toenails and fungus - ways to treat them responsibly


Why is my toenail black?

Our legs give us strength, support, and motion. However, we often neglect taking care of our feet which can lead to unsightly and sometimes painful repercussions. 

 Image of smooth and clean feet

Your toenails are made up of keratin, the same protein that makes up your skin and hair. Toenails are the hard flat part that protects your toes. They are resilient to daily wear and tear. 

The human body gives many subtle indications when something is wrong. A black toenail can be due to various causes such as an underlying medical condition, physical injury, secondary to any drug intake, etc.

Why is my toenail black? 

Sometimes a small black spot on the toenail can spread, turning your entire toenail black. There are several causes that lead to the black toenail. 

Athletes are more vulnerable to encounter a black toenail due to physical trauma. In some cases, it may even advance to a fungal infection caused by black toenail fungus and spread to other parts of the body. 

Black toenail also develops when you have an underlying ailment such as,

  • Diabetes
  • Kidney Problems
  • Heart diseases
  • Skin diseases like psoriasis or lichen planus
  • Anemia
  • On other immuno-suppresant drugs

If you are a diabetic, you must get your black toenail checked by your doctor. In very rare cases, a black toenail is an indication of melanoma, malignant skin cancer. Hence, it is highly recommended that you see your doctor for the diagnosis and possible treatment. 

Image of a black toenail infected by fungus

What are the symptoms of a black toenail?

There are several causes of the black toenail. This abnormality can change the appearance of your toenail and can even be painful in some cases.

Black Toenail Fungus

Fungal infection in nails is majorly caused by dermatophytes. Dermatophytes are a group of fungus that thrives on keratin, infecting your toenails, skin and hair. Fungal infections infect 10% of people in general.

Toenail infections can be due to a fungal infection or being in contact with an infected person. Walking barefoot in public places, where someone else with the infection has walked such as a sauna, or locker room can lead to developing a black spot on the toenail. Frequent exposure to damp or wet places such as swimming pools or living in a humid climate can also increase the risk of developing such infections. 

Initially, you may notice a white or yellow patch that deepens into abnormal discoloration and may even spread to surrounding skin. 

Fungi infect and spread in wet or damp areas the most. Therefore, people whose feet remain wet for a long period of time are most susceptible to these infections. Wearing ill-fitted or sweaty footwear  also increases the chance of contracting fungal  infection. 


Physical Trauma

Ill-fitted Shoes can cause black toenail

One of the most common causes of the black toenail is repeated trauma due to physical injury. Trauma can range from mild to severe injuries. Mild trauma can cause a minor blue or black spot and severe trauma can damage the blood vessels leading to clots and hemorrhages underneath your toenail. 

Physical trauma can be due to stubbing, dropping something very heavy on your feet, or wearing ill-fitted shoes. Runners and ballet dancers are very susceptible to such injuries. 

A single hit can cause severe damage, hence repeated trauma because of running can cause more harm. Runners have black toenails mostly due to ill-fitted shoes, shoes smaller than your size, or shoes made up of plastic that do not let your feet breathe. 


Discoloration of nail

Discoloration of the nail plates is the least stressful cause of black toenails. Dyes from your shoes, nail polish, color stains can cause discoloration, changing the appearance of your nail plate.

Few antibiotics, drugs used to cure autoimmune diseases and anti-cancer drugs can also cause discoloration. The discoloration is not painful and will disappear once you stop using products causing it, reduce or stop drug intake or let the nail grow naturally and cut it.


Malignant Melanoma

Malignant melanoma, a type of skin cancer can also develop under your fingernail or toenail, causing hyperpigmentation in your nail plates. Melanoma is one of the most serious types of skin cancer with metastatic potential and it can spread to other parts of your body.

It grows gradually and is painless, hence it often goes undetected at first. Hence, you must get your black toenail checked by a dermatologist. A dermatologist would recommend a biopsy to diagnose the disease and suggest treatments accordingly.

What could cause a black toenail?

  • Hyperpigmentation (White, yellow, or black)

  • Thickened 

  • Foul-smelling 

  • Painful (in some cases)

  • Swelling or Redness

  • Discharge (due to fungal infections) 

How do you treat a black toenail?

If you have a black toenail, don’t panic. In most cases, it will simply grow out. However, in case of fungal infections or melanoma timely treatment is necessary.

If your black toenail won't grow out naturally, seek a doctor's help. Your doctor will examine your toenail, may poke a needle to drain the blood, prescribe a topical antifungal medication, or recommend a biopsy for microscopic examination.

Soak your toe in cold water for 20 minutes, dry your feet and then apply the anti-fungal ointment prescribed by your doctor. Once you are done, cover your toenail with a clean bandage. If your toenails begin to detach, you should file your nail to prevent further tearing. 

Avoid treating it at home, this procedure requires sterile conditions and a doctor’s office. Treating it at home can aggravate the infection and increase the chances of spread. Black toenail due to an underlying ailment needs immediate attention and a doctor’s intervention or opinion. 

Home Remedies

Your doctor may prescribe oral antifungal medicines such as terbinafine or fluconazole to treat black toenails. However, these medicines come with few side effects such as dizziness, upset stomach to more alarming ones such as jaundice and other skin problems, hence must be taken only under medical supervision and after thorough evaluation of extent of involvement. 

Therefore, people can try some home remedies to treat their toenails,

1. Tea Tree Oil

According to the National Center for Complementary and Integrative Health, tea tree oil is a herbal medicine that has antiseptic and antifungal properties. Apply a   small amount of oil on the infected area with a cotton swab daily. 

2.  Vinegar 

 Another effective home remedy is using apple cider vinegar. Vinegar has acetic acid proven to have antifungal properties. Diluted in water vinegar can be used as a foot soak. Soaking your feet in a vinegar foot soak daily can treat black toenail fungus. The ratio can be one part vinegar and two parts of water. If the infection is extreme then a heavy soak is required to reduce the infection.

3.  Ozonized Oils

 A study in 2011, reveals that low concentration and short exposure to ozonated oils inactivate bacteria and fungi. Ozonated oils are sunflower oil or olive oil injected with ozone gas. Research suggests that ozone injected sunflower oil has been effective in treating black toenails. 

4.  Oregano Oil

 Oregano oil contains thymol which has anti-bacterial and antifungal properties. Applying oregano oil twice has shown a reduction in black toenail fungus. A combination of oregano oil and tea tree oil is also an effective home remedy to treat fungal infections.

5.  Garlic

Garlic has potent anti-microbial properties. It can be chopped and applied to the infected toenail for half an hour. Garlic can also be taken as a supplement. However, people with ulcers, stomach infections, or bleeding disorders must consult their doctor before taking these supplements.

6.  Changes in diet

 Your diet may be contributing to fungal growth. Reducing excess sugar and carbohydrates from your diet, avoiding alcohol, and incorporating probiotics, garlic, and ginger into your diet can help reduce the infection.



When to see a doctor?

You must see a doctor when you see some abnormalities in your toenail such as redness, white or black lines, swelling, pain, pus discharge, etc. You can try a few home remedies however if you don’t see any significant change then you must consult your doctor. 

How do I prevent black toenails?

Prevention is less expensive than cure. There are many ways to prevent a black toenail altogether, the following points can help eliminate the risk altogether,

  • Trimming your nails regularly, straight across and not rounded

  • Selecting shoes that fit correctly

  • Avoid walking barefoot in wet or damp public places

  • Wear protective footwear when handling heavy things

  • Maintaining good hygiene routines to avoid fungal infections

  • Wearing clean socks and shoes made up of natural materials

  • Walk barefoot at home to let your feet breathe 

  • Treat nail issues at an early stage


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