Brown Nails

When it comes to taking good care of the nails, people think that it is just enough to cut, trim, and decorate it.

Don’t you know that your nails can say something about your health? The normal color of the nails is white to light brown with pinkish to reddish tinge. The pink to red discoloration is caused by the flow of blood underneath the nail bed. If the nails are abnormally discoloured, it could indicate an underlying problem. (1, 3)

What does brown nails mean? A brownish discoloration of the nail is medically called melanonychia. It can affect a portion of the nail or the entire nails. It is also common during pregnancy, but nails turning black during pregnancy is alarming and warrants immediate medical attention. The discoloration may appear as spots, a band, or a streak. (2)

What causes brown nails?

  • Onychomycosis – It is an infection caused by fungi, the very same group of fungi responsible for causing ringworm and athlete’s foot. It attacks any parts of the body including the nails.
  • Psoriasis – it is an autoimmune disease wherein the immune system of the body targets the skin. It makes the skin itchy, rough, and silvery in appearance. It also causes discoloration of the fingernails and toenails. (5, 8)
  • Nutrient deficiency – Brown streaks in fingernails could indicate that your body lacks vitamins and nutrients, especially vitamin B12 and zinc.
  • Trauma – Any trauma to the nails causes discoloration. Factors leading to nail trauma include biting of the nails, presence of foreign body under the nails, and a sudden impact on the nails. It can cause brownish, bluish, to blackish discoloration of the nails.
  • Electromagnetic – Exposure to intense rays of the sun for a long period of time or repeated exposure to radiation can lead to discoloration of the fingernails.
  • Nevus – It is a circular brown moles on the skin. In layman’s term, it is called birthmarks or beauty marks. This condition is benign, but there is also a possibility of developing skin cancer on the nevus site. It can also cause brown spots on nails. (9, 10)
  • Exposure to harmful substances – Vertical brown lines on nails or total nail discoloration can be caused by strong substances such as iodine, arsenic, mercury, fluoride, and thallium.
  • Side effects of medications – Some drugs can cause brownish to blackish discoloration of the nails. Examples are antibiotics, anti-retrovirals, corticosteroids, chemotherapeutic agents, psoralens, phenytoin, gold salts, and some tricyclic antidepressants. (2, 3)
  • Genetic/Hereditary – Some genetic conditions can cause discolorations of the nails such as keratosis follicularis and acrodermatitis enteropathica. Keratosis follicularis is a rare genetic condition affecting the skin due to defect in transporting calcium into the cells leading the cells to stick together in an abnormal manner. On the other hand, acrodermatitis enteropathica pertains to the body’s inability to absorb zinc from the intestine secondary to genetic coding defect. This condition makes the body deficient of zinc.
  • Hormonal disorders – If you have a problem in the endocrine system, you will most likely have brownish discoloration of the nails. There will be an abnormality in the level of hormones in the body. Examples of endocrine disorders leading to unusual nail color include hyperthyroidism, Addison disease, Cushing syndrome, and diabetes mellitus. Brown fingertips symptom is common in people with Addison disease along with darkening of the skin. The same thing goes for people with Cushing syndrome. (4, 5)
  • Cancer – Certain types of cancer cause skin discoloration including brown discoloration of the nails. This includes basal cell carcinoma or malignant melanoma. It comes to a point wherein the cancer already affects the nail bed, although it rarely happens. A subungual melanoma is a malignancy affecting the fingernail. Brownish discoloration of the nails can also be associated with breast cancer. If there is an abnormal discoloration of the nails, it should be investigated the soonest time possible. (7)
  • Lifestyle – Don’t you know that the lifestyle you have can significantly affect the color of your nails. Frequent use of nail polish can cause abnormal discoloration of the nails primarily because of the chemicals present in the nail polish. Cigarette smoking can drastically affect the color of your nails too. To significantly improve the color and condition of your nails, you should take a break from smoking and nail polish use. Allow the new nails to grow. (2)
  • Other pertinent health problems – Aside from the skin, the nails are indicators that something is not right in your body. If you have nail discoloration such as dark spots or streaks in the nails, it could suggests health problems such as lung problems, diabetes, lupus, arthritis, liver disease, lymphatic system disorder, nutritional deficiency, AIDS, and so on. Hence, if you notice any unusual color change in your nail, then you need to seek immediate medical attention. This is to determine the root cause of the problem and to come up with the most appropriate treatment. (3, 6)

Brown Nails Discoloration Treatment

The treatment for nail discoloration primarily depends on the factors that cause it. It the discoloration is severe, then you need to see your doctor. He will come up with the best treatment plan that suits your condition.

Meanwhile, there are simple measures you can do in your home to significantly improve the condition of your nails. These are the following:

  • Maintain a proper hygiene – It is important to keep the body clean at all times. Keep in mind that harmful substances are everywhere and they are just waiting for the opportunities to strike. Make it a habit to wash your hands and feet regularly. Make sure your feet are dry before wearing socks and shoes. (7, 8)
  • Avoid walking barefooted – You should refrain walking barefooted, especially in public facilities to prevent acquiring dreadful disease. (3)
  • Keep your nails short – Longer nails can easily catch microorganisms. They are also prone to rubbing, which increases the possibility of the nails to lift from its bed. Make sure that you keep your nail short so that it does not extend beyond the nail bed.
  • Keep your feet cool – if your feet sweat a lot, you can prevent sweating by using talcum powder. You should also wear well-fitted shoes to allow your feet to breathe.
  • Choose the right nail products – Many nail care products contain strong chemicals, which can be potentially harmful to the nails. It is important to be choosy when it comes to using nail care products. If there is a severe discoloration of the nails, the best thing to do is to refrain from using any types of nail care products. (5, 7, 9)
  • Apply vinegar – Vinegar is a mild form of acid and is helpful in treating nail discoloration caused by bacterial infection. (4)



Published by Dr. Jackie Te RN, MD under Skin.
Article was last reviewed on January 12th, 2022.

Leave a Reply

Back to Top