It is important to keep your fingernails healthy for more than just cosmetic reasons. Your fingernails can provide clues to your overall health and signal any health issues. Gabriela Czapek, Registered Dietitian at CHA HPMC, explains by answering some common questions.

Is it common for diseases and conditions to affect your nails? If so, can you share examples of how they’d change your nails?
It is quite common for nails to be affected by diseases. Nails should be naturally smooth, translucent in color, slightly curved and firmly attached to the nail bed (nail bed with brisk capillary refill). For example, Chronic Obstructive Pulmonary Disease (COPD), heart failure, aortic stenosis, diabetes, lupus, and chemotherapy can affect your nails by making them look like spoon-shaped—a condition called Koilonychia. This happens as a result of the nutritional deficiencies caused by these conditions.1

  • Not enough oxygen in your bloodstream can cause blue nails.2
  • Liver disease and diabetes can cause white nails.2
  • Anemia causes pale nails.2
  • Kidney disease can cause half pink and half white nails.2
  • Lung disease and nail infections can cause yellow nails.2
  • Lupus, heart disease, alopecia areata (sudden hair loss), arthritis, and dermatomyositis
  • (inflammatory disease causing muscle weakness and rashes) can cause dusky red half-moons.2

  • Poisoning can cause blue half-moons.2

What kinds of nail abnormalities are associated with vitamin/mineral deficiencies?

  • Iron deficiency causes nails to be spoon-shaped.1 Iron deficiency anemia (lack of adequate healthy red blood cells) can cause pale nails.1
  • Selenium also plays a role in keeping our hair and nails healthy and its deficiency can cause brittle nails.4
  • Vitamin B12 deficiency presents as hyperpigmentation of nails with bluish discoloration, blue-black pigmentation with dark longitudinal streaks, and longitudinal and reticulate darkened streaks.5
  • Beau’s lines are horizontal ridges in the nails thought to be due to temporary disturbance of the nail matrix, which can include injury, an episode of paronychia or systemic illness, such as infection, and many chronic illnesses, including diabetes.

Nail changes can start to appear within a month after an acute event and remain visible for five to six months in thumbnails and two years in big toenails.3

If you do notice a change in your nails, should you see a doctor?
Yes, it is advised to consult a doctor or board-certified dermatologist if you notice any changes to nails.

Are there other non-alarming factors that can cause changes in nails?
Skin infections and nail infections are common and can cause a changes to nails.

What other diseases or health conditions can cause nail abnormalities?

  • People with diabetes can see effects of this disease in their skin and nails. Diabetes can cause circulation problems and neuropathy. This in turn can cause unhealing wounds, mainly in the body’s extremities. Also, reduced circulation, which can also be caused by other diseases, can leave the nails thin and brittle that can break and split and separate from the nail bed (onycholysis).3
  • Melanoma, a form of skin cancer, can manifest as a change in nails if a fingernail or toenail has a new or changing dark streak.2
  • Physical injuries can cause blood to be trapped under the nail bed and can also cause a temporary change in the shape of the nail. It can eventually go away as the nail grows out.
  • Aggressive manicures/pushing cuticles back to thumbnails can cause washboard nails. Grooves and ridges in the center of your thumb can develop as an effect.2
  • Fungal infections, psoriasis, and injuries can all cause the nail to lift up in a way that it’s no longer completely attached.2
  • Lung disease and rheumatoid arthritis can cause yellow nails. Wearing red nail polish without a base coat or smoking can also turn your nails yellow.2 Some nail infections can also cause yellow nails. It may not always be easily distinguishable, but it is good to keep a note of all of these contributing factors.
  • A fever, injury, chemotherapy, or major stress can cause your nails to grow slowly or stop growing.2 If you cannot think of what could have caused your nails to grow slowly or stop growing, consult your dermatologist or primary care doctor. Once you find and treat the cause, nails, most often, start growing normally once again.

1L. Kathleen Mahan, Janice L. Raymond. “Krause’s Food & The Nutrition Care Process” 14th Edition. Elsevier, 2017.
2American Academy of Dermatology Association.
3Rowan Hillson, Wiley Clinical Healthcare Hub. 11 September 2017.
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