by Chris D. Meletis, ND
What if you could tell some important things about your health just by looking at your fingers or toes? As it turns out, our fingernails and toenails can tell us a lot about our health because the state of our nails mirrors the state of our bodies.
Changes in the health of our nails are linked to everything from lung health and hyperthyroidism to heart problems and inflammatory bowel disease. When your nails don’t look their healthiest, it may go beyond a cosmetic issue and indicate it’s time to check with your doctor.
In this article, I’ll describe how the condition of your nails paints a picture of your overall health. You can use this article to launch a discussion about nail health with your own healthcare practitioner.
Yellow Nail Syndrome
This condition results in slow-growing, over-curved, thickened nails. As you can guess from the name of the condition, the nail is tinted yellow. Additionally, the lunula (the white half-moon at the bottom of your nail) is absent.
Yellow nail syndrome often occurs together with lung abnormalities, including pleural effusion, when excess fluid accumulates between the two pleural layers of the lungs, the fluid-filled space that surrounds your lungs. Yellow nail syndrome also can show up together with the chronic obstructive lung disease known as bronchiectasis. Other causes of yellow nail syndrome include:1-5
- Recurrent sinusitis
- Respiratory tract infections
- Pericardial effusion (fluid around the heart)
- Eye abnormalities
- Hypoalbuminemia (low albumin levels in the blood)
- Internal malignancies
- Rheumatoid arthritis—usually due to the effects of drugs used to treat RA
What causes yellow nail syndrome? Researchers don’t know for sure. One theory is that it has to do with the lymphatic system becoming blocked.6 Another possibility involves microvascular permeability, when the small blood vessels become more permeable, allowing substances in the blood such as protein to escape throughout the body.7
Onycholysis occurs when the nail plate is separated from the nail bed, turning the affected area white. The most common cause is trauma, but periungual warts are another possibility. This condition also occurs simultaneously with psoriasis. In this case, onycholysis affects the tip of the nail.
If there’s no obvious cause for the onycholysis, hyperthyroidism is a possibility. Onycholysis occurring with hyperthyroidism is often called “Plummer’s nails.” When nails turn brown, this is also often a sign of hyperthyroidism.1
Furthermore, researchers have linked niacin deficiency to onycholysis.8
Pitting of the nails, a depression in the nail plate, affects 10 to 50 percent of patients with psoriasis.9 Other systemic diseases cause pitting, including:
- Reiter’s syndrome (a type of arthritis that develops in response to an infection in another part of the body) and other connective tissue disorders
- Sarcoidosis (a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs)
- Pemphigus (a rare group of blistering autoimmune diseases affecting the skin and mucous membranes)
- Alopecia areata (hair loss)
- Incontinentia pigmenti (a genetic disorder that affects the skin, hair, teeth, nails and central nervous system)10
Any localized dermatitis—such as atopic or chemical dermatitis—disrupting orderly growth in the superficial nail plate also can result in pitting.
In clubbing, the soft tissue beneath the proximal nail plate—the end of your nail where it is attached to your finger—thickens, resulting in sponginess in that area of the nail.11
Your healthcare practitioner can diagnose clubbing using the “Schamroth’s test,” originally demonstrated by South African cardiologist Dr. Leo Schamroth on himself.
Scientists aren’t completely sure what causes clubbing. One theory is that the condition occurs when the lungs don’t do a good enough job at filtering bone marrow cells called megakaryocytes and platelet clumps, causing them to enter the systemic circulation. Once this happens, platelets may release platelet-derived growth factor at the nail bed, causing the changes associated with clubbing.12
Clubbed nails are also sometimes linked to the abnormal proliferation of cells in the lung, bronchiectasis (an obstructive lung disease), lung abscess, empyema (collection of pus in the lungs), pulmonary fibrosis and cystic fibrosis.1 Other conditions associated with clubbing include:1,13
- Arteriovenous malformations (abnormal connections between veins and arteries)
- Fistulas (an abnormal connection or passageway between two organs or vessels that normally don’t connect)
- Celiac disease
- Congenital heart disease
- Endocarditis (inflammation of the inner layer of the heart)
- Graves’ disease
- Inflammatory bowel disease such as Crohn’s
When clubbing occurs separate from a known disease, your doctor may look into the possible presence of bronchogenic carcinoma (lung cancer) or another reason for the finding, keeping in mind that 60 percent of clubbing cases aren’t associated with any disease.14
When the nail is “spoon-shaped,” it’s called koilonychia. In this condition, nails lose their convexity, flattening out or even becoming concave. In infants, this is often a harmless condition resolving itself by age three. If you have this condition as an adult, the culprit may be trauma or constant occupational exposure of the hands to petroleum-based solvents. Another possible cause is nail-patella syndrome,15 a genetic condition that includes easily dislocated knee caps, kidney and skeletal abnormalities and glaucoma.
Koilonychia is also associated with iron deficiency, with or without anemia, and it occasionally occurs in patients with hemochromatosis (iron overload).16 When spooning is present without an obvious associated illness, your physician will likely want to obtain a complete blood count and ferritin level test to help rule out iron deficiency and hemochromatosis.
At the University of California Renal Center, researchers have discovered that approximately one in three hemodialysis patients have imbalances in copper, zinc and protein and these imbalances are linked to koilonychia.8
Beau’s lines are deep, grooved lines that run from side to side horizontally on the nail plate in most or all of the fingers. Any condition severe enough to disrupt normal nail growth may cause Beau’s lines such as coronary occlusion, low calcium levels, diabetes or psoriasis.1 Chemotherapy drugs also can cause these lines. Other culprits include zinc deficiency, trauma and exposure to cold temperatures in patients with Raynaud’s disease.1,17-18,8
Because nails grow about 1 mm every six to ten days, your doctor can estimate when a disease began by measuring the distance from the line to the nail bed.1
Pairs of transverse (side to side) white lines extending across the nail are called Muehrcke’s lines. An abnormality of the vascular nail bed, these lines disappear while the nail is pressed and blood is squeezed from the vessels beneath the nail.
One characteristic of Muehrcke’s lines is that they don’t move with nail growth because they’re located in the nail bed. In addition, Muehrcke’s lines are always parallel to the edge of the lunula.
Clinicians may observe Muehrcke’s lines in patients with hypoalbuminemia (i.e., albumin level less than 2 g per dL [20 g per L]). Albumin is an important protein in the human body and low levels can lead to an increase in free ionized calcium. Muehrcke’s lines disappear when the protein level normalizes. Muehrcke’s lines may also appear in patients with nephrotic syndrome, liver disease and malnutrition.1
Leukonychia are the white lines or spots that dot the nails. It can occur either in patches or involve the entire nail.19 Leukonychia partialis is nonuniform, pops up on different places on different nails and does not go across the entire nail. The cause is controversial.
Many conventional and alternative practitioners believe the white spots are always caused by minor trauma to the proximal nail bed. There are no studies to show this conclusively, just as there are no studies to show conclusively that zinc supplementation resolves the white spots. However, in many patients, there is complete and consistent resolution of the white spots after zinc supplementation.
Accentuated ridges in the nail surface commonly occur as a normal part of aging. When nails are thin and lusterless with a sandpapered appearance, this is called trachyonychia. When all the nails take on this sandpapered appearance, the condition is referred to as 20-nail dystrophy. Conditions that sometimes go hand in hand with 20-nail dystrophy include:
- Alopecia areata (hair loss)
- Atopic dermatitis
- Vitiligo (depigmentation of the skin)
- Lichen planus (a condition occurring in the skin and mouth that causes lesions or rashes)20-21
Red or brown longitudinal (top to bottom) thin lines occurring beneath the nail plate are known as splinter hemorrhages, visible when capillaries within the epidermal ridges leak. Splinter hemorrhages are a sign of endocarditis, if they are present at the part of your nail that attaches to the finger rather than at the tip of the nail plate. They’re more common in subacute than acute infections22 and occur in 15 percent of patients with endocarditis.23 Other causes of splinter hemorrhages include local trauma, psoriasis or localized fungal infection.
There are so many causes of splinter hemorrhages that researchers have questioned their usefulness as an isolated sign of illness. They’re of more concern when they’re accompanied by:1
- Roth’s spots (retinal hemorrhages)
- Osler’s nodes (painful, red, raised lesions found on the hands and feet)
- Janeway lesions (non-tender, small lesions on the palms or soles)
- Heart murmur
It’s also important to note that vitamin C imbalances may occur side by side with splinter hemorrhages.8
Color Changes in Nails
The half-moon-shaped lunula can offer clues to your health. For example, in people who have Wilson’s disease (hepatolenticular degeneration), this area is blue (called azure lunula). Heart failure can turn the lunula red, and tetracycline therapy can turn it yellow. Excessive fluoride ingestion can turn nails brown or black, while people with pale nail beds may have iron deficiency.1,8
Your doctor may suspect severe liver disease (usually cirrhosis) when the lunula disappears and most of the nail plate turns white (looking similar to ground glass)—a condition known as Terry’s nails.24-25 Usually, this occurs on all fingers, although it may appear on only one. Eighty percent of patients with cirrhosis have Terry’s nails.1
In addition, one study found that 23 to 25 percent of hospitalized patients with varied diseases had Terry’s nails. A decrease in vascularity and an increase in nail bed connective tissue are thought to cause Terry’s nails.1
Half and Half Nails
An outward manifestation of chronic renal disease, Kawasaki’s disease, cirrhosis and zinc deficiency is half and half nails.1 This occurs when production of the pigment melanin—the same pigment responsible for skin color and the tanning of skin—increases, which may cause the tip of the nail to turn brown. Renal disease can cause the portion of the nail bed that’s connected to the finger to turn white and the lunula to disappear, giving the nail a half-brown, half-white appearance.
Five case studies also indicate half and half nails may occur in Crohn’s disease patients.26-27 Although scientists need to investigate further, the Crohn’s connection makes sense, given that Crohn’s patients are often zinc deficient due to poor absorption in the colon and zinc deficiency is linked to half and half nails.
You’ve Got It Nailed
We can tell a lot about our health by the state of our nails. If your nails aren’t looking too healthy, you’ll find it helpful to talk with your doctor. You’ll also want to make certain your iron levels are normal in order to avoid some of the nail problems mentioned above.
When my patients test low for iron, I start them on an iron supplement. Zinc supplementation as well as a good multinutrient can also help to make certain you have a good foundation for not only nail health but overall health as well.
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