Fingernail Colors - What Does They Mean For Your Health?

Color of Nails As A Health Indicator

Most cases of abnormal fingernail health are simply a result of nonspecific reaction to trauma, or other benign occurrences. Less commonly, a change in any part of the nail or nail colors may indicate systemic disease. The nail plate, bed, and surrounding tissue can be affected differently by a single-organ disease, systemic diseases, nutritional deficiencies, and toxic insults.

Clinically recognizable nail conditions may have different appearances along a wide spectrum. These changes can be textural changes, nail color changes, as well as changes in shape, width and length and, in extreme cases, nail loss. Change in the nail color known as dyschromia can be sign of localized disease, from causes such as injury or infection, especially when limited to a single or small number of nails. In contrast, discoloration that resembles the shape of the lunula (the crescent-shaped white area of the proximal nail bed sometimes call nail-moons), that involves multiple nails may indicate a more global issue in the body. (Figure 1)

Figure 1. Anatomy of the Fingernail

Credit: Cunliffe, Tim, 2016^[40]

 

Yellow Nails

Yellow nails can be a normal occurrence in the elderly, but it may also develop in association with use of medications or systemic diseases. Yellow discoloration can be from systemic conditions such as jaundice, inflammatory skin conditions, and even eating too many carrots.^[1] Yellow nail syndrome is a specific medical condition that can lead to yellow nails. Although yellow nail syndrome is rare, it is important to ask your doctor or health care provider about yellowing nails. Notably, not all incidences of yellowing nails indicate a diagnosis of yellow nail syndrome.

Yellow nail syndrome

The origin of yellow nail syndrome remains a mystery, with proposed mechanisms pointing to a decrease in lymphatic drainage. Lymph is composed of a rich mixture of different components. It transports proteins and fats and helps with the movement of immune cells. Slow lymph movement may result in the deposition and oxidation of fat molecules in the nail.^[2,3] Additionally, subsequent protein leakage from various blood vessels may contribute to the yellow discoloration. When yellow nails appear in combination with breathing difficulties and swelling of the lymph nodes, the term yellow nail syndrome is used to describe this triad.

This syndrome presents with a decrease in nail growth, thickening and hardening of the nail, and has been reported in conjunction with many conditions including, but not limited to, endocrine disorders, connective tissue disease, and cancer.^[4-6] It is thought that correcting the underlying issues that lead to the syndrome and result in impaired lymphatic drainage might be a reasonable approach to improving the yellow nails. Reports of single patients have described poor arterial circulation and other vascular disease in patients with yellow nail syndrome.^[7] These findings as well as a reported cure of yellow nails after the successful management of respiratory disturbance support the idea that problems with blood circulation may also explain the cause of yellow nail syndrome.^[8]

Red Nails

Red nails, or rubronychia, are most often associated with discoloration of the nail plate from exposure to staining agents such as over the counter creams that consist of octisalate and hydroquinone.^[39] Red lunulae (the crescent white area on the nails) are also seen with several systemic diseases. Cardiovascular diseases such as angina, congestive heart failure, hypertension, and heat attack are all included.^[9] Respiratory conditions associated with red lunulae are chronic bronchitis, chronic obstructive pulmonary disease and emphysema. Anemia, liver and kidney disease, as well as a host of other cancers and auto immune diseases, like alopecia areata, have presented in conjunction with red lunulae.^[10-12]

Blue Nails

Blue discoloration of the nails is mostly limited to the lunula of the nail. Blue lunulae do not commonly indicate systemic issues, but have been reported in approximately ten percent of adult patients with Wilson’s disease, a rare inherited disorder where copper isn’t eliminated properly from the body and accumulates.^[13] Blue lunulae are more often related to the use of medications such as antimalarials and chemotherapy drugs.^[14-16] Blue nail can also be observed with chemical exposure to silver, or the ingestion of supplemental colloidal silver.^[17,18] Even more rare, bluish discoloration of the entire nail can also be found in patients with vitamin B12 deficiency, the hue quickly reversing with nutritional replenishment.^[19] Blue nails may also be acquired in patients with HIV/AIDS or inherited, developing in association with disease of the nails' blood supply or normally in persons with darker skin pigmentation.^[20,21]

Black or Brown Nails

Brown to black nails, or melanonychia, develops from the deposition of melanin, the molecule responsible for the pigmentation of our skin, into the matrix of the nail. Typically, this pigmentation occurs as a strip spanning the length of the nail longitudinally. These lesions almost always appear on a single nail, and may be normal pigmentation, simply drug-induced, or can indicate disease. Frequent drugs that cause darkening of the nail include antimalarials (chloroquine, quinacrine, hydroxychloroquine), antiretrovirals, and chemotherapeutics (cisplatin, doxorubicin, docetaxel), hydroxyurea, and minocyclin.^[22,23] Nutritional deficiency of vitamin B12 has been reported to cause reversible pigmentation.^[24] Hormonal fluctuations, like those seen in pregnancy or adrenal insufficiency, can cause similar nail patterns.^[25-28] Other causes include exposure to radiation, fungal infection, moles, melanoma, and inflammatory disorders. ^[29]

White nails

White nails, or leukonychia, can be classified in two ways based on where the pathology originate. True leukonychia originates in the matrix. Apparent leukonychia originates in the nail bed. In true leukonychia there is abnormal keratinization of the nail matrix, parakeratosis within nail plate, and opaque appearance of the nail on exam. The white discoloration is unaffected by pressure and moves distally as the nail grows. Apparent leukonychia refers to abnormal nail bed vasculature. This white opacity will blanch with pressure and is unaffected by nail growth.^[30]

True leukonychia can be seen in inherited disorders such as Darier Disease and Hailey-Hailey Disease.^[30-32] Leukonychia punctata is a true leukonychia that usually occurs after trauma as punctate white spots. Sometimes true leukonychia can present as transverse white lines called “Mee’s Lines.” Mee’s lines are horizontal white bands that span the width of the nail. They are most commonly seen in arsenic poisoning but are attributed to numerous systemic diseases such as acute renal failure, heart failure, ulcerative colitis, breast cancer, measles, and systemic lupus erythematosus.^[30,33]

Apparent leukonychia can be classified as either Muehrcke nails, half and half nails, or Terry’s nails. Terry’s nails are generally seen in hepatic cirrhosis, but can be seen in congestive heart failure, diabetes mellitus, pulmonary tuberculosis, reactive arthritis, Hansen Disease, and peripheral vascular disease. These nails present as white discoloration of the entire nail except for a 1-2 mm pink brown band at the distal free edge.^[34] Half and half nails, or Lindsay nails, are seen as a 20-60% distal segment of pink brown with a transverse border contrasting with proximal leukonychia that obscures the lunula.^[35] Lindsay nails are seen in patients with chronic renal disease, Behcet disease, Crohn’s disease, Kawasaki disease, pellagra, and zinc deficiency.^[33] Meuhrcke lines are paired transverse white bands that span the width of the nail and are parallel to the distal lunula. Muehrcke lines are seen commonly in patients with hypoalbuminemia, nephrotic syndrome, liver disease, malnutrition, HIV or AIDS, and those undergoing chemotherapy.^[36] Recently, leukonychia has been described in patients suffering from COVID-19.^[37,38]

 

Consult Your Doctor

It is important to recognize early possible signs of systemic, possibly catastrophic, disorders. It is equally important to note that most presenting nail changes are completely harmless, and what could be harmful is the negative effects of anxiety as a result of self-diagnosis. Remaining in touch with one’s body, and aware of changes as they occur is an invaluable trait in understanding oneself. Self-examination, both mental and physical, can be an essential key to preventative heath, but one must recognize when investigation may be leading to anxieties. While still listening to your intuition when you have concern, always consult your doctor before maintaining the belief that you have any condition.