Nail discoloration, in which the nails appear white, yellow, or green, can result from different infections and conditions of the skin. In about 50% of cases, discolored nails are a result of infections with common fungi that can be found in the air, dust, and soil. There are many species of fungi that can affect nails. By far the most common, however, is called Trichophyton rubrum. This type of fungus has a tendency to infect the skin and is therefore known as a dermatophyte. Pseudomonas is a type of bacteria that infects the nail bed and results in a greenish color to the nails. Red or black (that may sometimes appear bruised) nails may result from a hematoma (a collection of blood) under the nail as a result of trauma (including ingrown toenails).
Chronic medical conditions also can affect the appearance of the nails. Specific color changes in the nails can be suggestive of diabetes or of liver, kidney, heart, or lung conditions. This is why doctors pay specific attention to nails during a routine physical examination.
Other, rare causes of discolored nails include the "yellow nail syndrome," an inherited condition that results in slow-growing, yellowing, discolored nails and is associated with lymphedema (swelling of tissues due to the accumulation of fluid) and lung diseases. Nails may also appear lightened to a whitish-yellow color if there has been separation of the nail from the nail bed, termed onycholysis.
The skin, mucous membranes, and nails may appear blue when there is inadequate oxygenation of blood (cyanosis), but this is not true discoloration of the nail itself.
Other causes of nail discoloration
- Bacterial Infection
- Chronic Lung Diseases
- Drug Hypersensitivity (for Example, Tetracycline)
- Senile Ischemia (Onychogryphosis)
- Staining From Nail Varnish or Cosmetic Products
- Yellow Nail Syndrome
Pictures, Images, Illustrations & Quizzes
Foot Problems: Why Are My Toenails That Color?
What can the color of your toenails tell you about your health? Watch for these shades to know if you need to talk to your doctor.
Ingrown Toenails: Infection, Causes, Prevention, Surgery
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Nail Disorders: What Nails Say About Your Health
Nail disorders problems may be a sign of disease in the body. Nails can be spoon-shaped, blue, or have white lines. Some nail...
Picture of Discoloration of Nail Plates
Many chemicals can discolor nail plates. Solutions of potassium permanganate and silver nitrate stain nail plates brown-purple...
Picture of Fingernail Anatomy
A fingernail is produced by living skin cells in the finger. See a picture of Fingernail Anatomy and learn more about the health...
Picture of Fungal Nail Infection
Nails that are infected with a fungus may become discolored (yellowish-brown or opaque), thick and brittle, and may separate from...
Picture of Ingrown Toenail
A common disorder that occurs when the edge of the toenail grows into the skin of the toe particularly on the big (great) toe....
Picture of Onychomycosis (Fungal Nail Infection)
The most common fungus infection of the nails is onychomycosis. See a picture of Onychomycosis (Fungal Nail Infection) and learn...
Causes of Nail Discoloration
Eczema is a general term for many types dermatitis (skin inflammation). Atopic dermatitis is the most common of the many types of eczema. Other types of eczema include: contact eczema, allergic contact eczema, seborrheic eczema, nummular eczema, stasis dermatitis, and dyshidrotic eczema.
Can a Nail Grow Back if Removed?
Yes, nails have good regeneration capacity, but they grow slowly. Fingernails may grow one-tenth of a millimeter each day, so completely removed fingernails usually grow within 6 months. Toenails may grow at about one-half or one-third the rate of the fingernails, so completely removed toenails may grow within 18 months.
Diabetes (Type 1 and Type 2)
Diabetes is a chronic condition characterized by high levels of sugar (glucose) in the blood. The two types of diabetes are referred to as type 1 (insulin dependent) and type 2 (non-insulin dependent). Symptoms of diabetes include increased urine output, thirst, hunger, and fatigue. Treatment of diabetes depends on the type.
Do You Have to Drain a Subungual Hematoma?
A subungual hematoma is bleeding under the nail. A doctor will drain your subungual hematoma only if it causes pain or is greater than 50% of the surface area of your nail. If blood is spontaneously draining from the hematoma, drainage of subungual hematoma is generally not required.
Fungal nails (onychomycosis) may be caused by many species of fungi, but the most common is Trichophyton rubrum. Distal subungal onychomycosis starts as a discolored area at the nail's corner and slowly spread toward the cuticle. In proximal subungal onychomycosis, the infection starts at the cuticle and spreads toward the nail tip. Yeast onychomycosis is caused by Candida and may be the most common cause of fungal fingernail.
Heart disease (coronary artery disease) occurs when plaque builds up in the coronary arteries, the vessels that supply blood to the heart. Heart disease can lead to heart attack. Risk factors for heart disease include: Smoking High blood pressure High cholesterol Diabetes Family history Obesity Angina, shortness of breath, and sweating are just a few symptoms that may indicate a heart attack. Treatment of heart disease involves control of heart disease risk factors through lifestyle changes, medications, and/or stenting or bypass surgery. Heart disease can be prevented by controlling heart disease risk factors.
Hypertensive Kidney Disease
High blood pressure can damage the kidneys and is one of the leading causes of kidney failure (end-stage renal kidney disease). Kidney damage, like hypertension, can be unnoticeable and detected only through medical tests. If you have kidney disease, you should control your blood pressure. Other treatment options include prescription medications.
Ingrown Toenail (Onychocryptosis)
Ingrown toenails are caused by the growth of the toenail into the surrounding nail fold. Symptoms and signs include toe pain, swelling, redness, and yellow drainage. Treatment at home involves soaking the affected foot in diluted white vinegar or Epsom salts, elevating the foot, and trimming the nails straight across. Surgery is also an option for severe cases. Prevent ingrown toenails by wearing shoes with a wider toe box and avoiding repeated injury to the toenails. Avoid curving or cutting the nails short at the edges.
Jaundice (Hyperbilirubinemia) in Adults
Jaundice (hyperbilirubinemia) in adults may be caused by a variety of medical diseases or conditions. Some cases of jaundice can be managed at home with a doctor's supervision, while other causes of jaundice may be life-threatening. Symptoms of jaundice are yellow skin, yellowing of the whites of the eyes, pale colored stools, dark urine, itchy skin, vomiting, nausea, and rectal bleeding. Treatment of jaundice is focused on the disease or condition that is causing jaundice.
Lichen planus is a common skin disease that features small, itchy pink or purple spots on the arms or legs. The abnormal areas on the skin in lichen planus are typically flat-topped (hence the term planus), itchy, and frequently have a polygonal or angular shape.
Liver disease can be cause by a variety of things including infection (hepatitis), diseases, for example, gallstones, high cholesterol or triglycerides, blood flow obstruction to the liver, and toxins (medications and chemicals). Symptoms of liver disease depends upon the cause and may include nausea, vomiting, upper right abdominal pain, and jaundice. Treatment depends upon the cause of the liver disease.
Lymphedema is a condition in which one or more extremities become swollen as the result of an impaired flow of the lymphatic system. There are two types of lymphedema: primary and secondary. Filariasis is the most common cause of lymphedema worldwide. In the U.S., breast cancer surgery is the most common cause. Symptoms include swelling of one or more limbs, cracked and thickening skin, and secondary bacterial or fungal infections of the skin. There is no cure for lymphedema.
Psoriasis is a long-term skin condition that may cause large plaques of red, raised skin, flakes of dry skin, and skin scales. There are several types of psoriasis, including psoriasis vulgaris, guttate psoriasis, inverse psoriasis, and pustular psoriasis. Symptoms vary depending on the type of psoriasis the patient has. Treatment of psoriasis may include creams, lotions, oral medications, injections and infusions of biologics, and light therapy. There is no cure for psoriasis.