Have you noticed a change to any of your nails lately? A change in color, texture, or shape can be harmless, but it can also be a sign of disease. If you notice any of the following changes to a fingernail or toenail, it’s time to see a board-certified dermatologist.
Melanoma under nailMedical name: Acral lentiginous melanoma
Dark streak If a fingernail or toenail has a new or changing dark streak, it’s time to see a dermatologist for a skin cancer check. That dark streak could be melanoma, the most serious type of skin cancer.
Not every dark streak is a melanoma, but it’s always good to have a dermatologist examine one. Caught early and treated, that may be the only treatment you need.
Allowed to grow, treatment becomes more difficult.
Fingernail lifting upMedical name: Onycholysis
Nail lifting up If a nail starts to lift up so that it’s no longer completely attached, you’ll likely see white discoloration, as shown here. When a nail lifts up, the cause is often:
Injury from an aggressive manicureInjury form cleaning under your nails with a sharp object
A dermatologist should examine any nail that’s lifting up. You may need treatment to clear an infection. A dermatologist can also give you some tips that may help the new nail grow out normally.
Infection around fingernailMedical name: Paronychia
Redness and swelling around a nail If you have redness and swelling around a nail, you may have an infection. When diagnosed early, you can often treat an infection with soaks and antibiotics. If an open sore forms, you’ll need more extensive treatment.
Infection under nailMedical name: Paronychia
Greenish black color When bacteria cause a nail infection, the nail can turn greenish black as shown here.
Without treatment, a nail infection tends to worsen. Treatment can get rid of your pain and tenderness and help clear the infection.
Fingernail with pitsMedical name: Pitting
Pitted nails If you have dents in your nails that look like they were made by an icepick, this could be a sign that you have a disease that affects your entire body.
Atopic dermatitisAlopecia areata
Seeing a board-certified dermatologist for a diagnosis is important. Dermatologists are the specialists who diagnose and treat these diseases. Treatment can help you feel more comfortable and prevent the disease from worsening.
Yellow nail syndromeMedical name: Yellow nail syndrome
Yellow nails Wearing red nail polish without a base coat or smoking can turn your nails yellow. If your nails turn yellow, thicken, and seem to stop growing, it could be a sign of something going on inside your body.
Lung disease and rheumatoid arthritis can cause yellow nails. You may also have a serious nail infection, which requires treatment.
Deep groove in nailMedical name: Beau lines
Deep grooves (or gaps) Lines that run the length of a nail are common and usually nothing to worry about. If you see deep grooves that run the width of your nail like the ones shown in this picture, it means that something slowed (or stopped) your nails from growing for a while.
When something causes your nail(s) to completely stop growing for a while, you may see a gap. If this happens, you’ll have a place on your nail(s) that’s missing nail. The medical name for this condition is onychomadesis (on-ah-coe-ma-dee-sis).
A fever, injury, chemotherapy, or major stress can cause your nails to grow slowly or stop growing.
If you cannot think of what could may have caused your nails to grow slowly or stop growing, see your dermatologist or primary care doctor. Once you find and get rid of the cause, nails often start growing normally.
Ram’s horn nails This happens when the nails thicken and overgrow. Some people get Ram’s horns because the condition runs in the family.
If you have a disease, such as psoriasis, ichthyosis, or circulation problems, you may also develop Ram’s horn nails.
Cutting and treating these nails requires help from a podiatrist or dermatologist.
Spoon-shaped nailsMedical name: Koilonychia
Thin, spoon-shaped nails If you have thin fingernails that dip down in the middle and look like spoons, you may not be getting enough iron. People develop an iron deficiency for many reasons, including:
Lack of proper nutrition
A health problem with their stomach or intestinesSensitivity to gluten (celiac disease)High altitude
Getting a proper diagnosis and treatment can help you feel better.
Washboard nailsMedical name: Onychotillomania
Washboard nails If you have grooves and ridges in the center of your thumb that look like the ones shown in this picture, you may have developed a habit of picking at (or pushing back) the cuticles on your thumbnails. Many people are unaware that they do this.
A dermatologist may be able to help you break the habit, allowing healthy nails to grow out.
Clubbing causes nails to curve downMedical name: Clubbing
Curved nails The curving can begin so gradually that many people are unaware it's happening. As the nails continue to curve downward, fingertips often swell and the nails start to feel spongy when pressed on.
If you notice your fingernails start to curve, it’s time to see a board-certified dermatologist. Curved nails can be a harmless trait, which runs in the family. Curved nails can also be a sign that you have a disease in the:
Lungs
HeartLiverStomach or intestine
Color change A disease inside your body can cause your nails to change color. Certain color changes can be a warning sign of a specific disease, as the following table shows.
Color
Disease or other health problem
Blue nails
Not enough oxygen in your bloodstream
White nails
Liver disease, diabetes
Pale nails
Anemia
Half pink, half white nails
Kidney disease
Yellow nails
Lung disease, nail infection
Dusky red half-moons
Could be lupus, heart disease, alopecia areata, arthritis, dermatomyositis
Blue half-moons
Could be sign of poisoning
Seeing a change to your nails or the half-moons doesn’t always mean that you have a disease.
Still, it’s important to see a board-certified dermatologist if you notice any changes. Board-certified dermatologists specialize in diagnosing and treating the skin, hair, and nails. They have the expertise to tell you whether the change is harmless or requires medical testing.
Images 4, 5, 7, 9, 10, and 11 used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.
Images 3, 12: Getty Images
Images from the Journal of the American Academy of Dermatology
Image 2: J Am Acad Dermatol. 2014;70(4):748-62.
Image 6: J Am Acad Dermatol. 2007;57:1-27.
Image 8: J Am Acad Dermatol. 2015;73:849-55.
References Braswell MA, Daniel CR, et al. “Beau lines, onychomadesis, and retronychia: A unifying hypothesis.” J Am Acad Dermatol 2015; 73:849-55.
Fawcett RS, Hart TM, et al. “Nail abnormalities: Clues to systemic disease.” Am Fam Physician. 2004;69(6):1417-24.
Kiaravuthisan MM, Sasseville D, et al. Psoriasis of the nail: Anatomy, pathology, clinical presentation, and a review of the literature on therapy.” J Am Acad Dermatol 2007;57:1-27.
Kumar V, Aggarwal S, et al. “Nailing the diagnosis: Koilonychia.” Perm J. 2012;16(3): 65.
Ring DS. “Inexpensive solution for habit-tic deformity.” Arch Dermatol. 2010;146(11):1222-3.
