Here’s What Your Nails Say About Your Skin Health

Did you know that the nails can actually provide important clues about your skin and overall health? Since the nails, skin, and hair are all made of a protein called, keratin, changes in your fingernails or toenails are often a reflection of underlying dermatologic conditions. From psoriasis to fungal infections to more serious issues like skin cancer, nail health and skin health are closely linked.

How Are Nails Connected to Skin Health?

Dermatologists often call nails the “windows” into a patient’s health. Skin and nails are made of keratin and grow in cycles influenced by nutrition, circulation, and environmental exposures. Subtle changes in the color, shape, or texture of nails can sometimes reveal skin diseases or systemic conditions before they show up elsewhere.

As such, recognizing nail changes early gives patients the chance to treat underlying problems sooner, whether it is a skin disorder or something more serious.

Common Nail Changes and What They May Indicate

Nail Color Changes

• Yellow nails: Xanthonychia, or yellow nail hue, is often caused by fungal infections, which can thicken and discolor the nail completely. Chronic skin conditions like psoriasis can also cause yellowing due to changes in nail growth. More commonly, long-term nail polish use may stain the nail, but patients may want to consult a dermatologist if the yellowing color persists long after polish removal as there can be an association with underlying vitamin deficiencies or other chronic diseases.

• White spots or streaks: Leukonychia, or white spots or streaks of the nails, are most commonly due to minor trauma, such as bumping or pressing the nail, and will usually resolve on its own without medical intervention, with natural nail growth. Repeated white patches, however, may suggest nutritional deficiencies, exposure to certain medications or heavy metals. chronic diseases, some hereditary conditions, or various skin conditions, including lichen planus and psoriasis, to name a few. Persistent white streaking should not be ignored, as it can indicate underlying health issues.

• Brown or black streaks: While dark streaks, or melanonychia, can sometimes result from bruising under the nail, medications, or infections, they may also signal melanoma, a serious form of skin cancer. Unlike trauma, melanoma-related streaks can increase in width over time as the nail grows and can expand onto the adjacent skin surrounding the nail (Hutchinson’s sign). This form of nail color change should be examined by a dermatologist as soon as possible.

Nail Texture and Surface Changes

• Pitting (tiny dents): Small depressions in the nail surface are a classic sign of psoriasis but can also occur with other dermatologic conditions, like alopecia areata. Pitting occurs when irregular growth disrupts the nail plate. Even mild pitting should be evaluated, as it may indicate underlying inflammatory skin disease.

• Ridges: Vertical ridges along the nail are usually harmless and develop more prominently with age. Horizontal ridges (also called Beau’s lines), however, may point to eczema, illness, or other systemic health events that temporarily halted nail growth. Multiple horizontal ridges across several nails can indicate more serious underlying conditions. New nail ridges, especially involving a single digit, should also be evaluated to rule out benign or malignant skin growths.

• Thickened nails: When nails become unusually thick, fungal infections are often the culprit. Thickened toenails may also develop in patients with nail trauma, hereditary conditions, chronic eczema or psoriasis due to inflammation around the nail matrix. These nails are often difficult to trim and may be painful when wearing shoes.

Nail Shape and Growth Changes

• Clubbing (curved nails): Nails that curve downward and appear bulbous can be linked to systemic health issues such as lung disease, malignancies, infections, hereditary conditions, heart, thyroid, digestive, or liver conditions, to name a few. In dermatology, clubbing can sometimes be seen in connective tissue disorders. If clubbing appears suddenly, it should be evaluated promptly.

• Brittle nails: Nails that crack, split, or peel easily may occur with aging, but can also indicate skin conditions like eczema, vitamin deficiencies, or thyroid imbalances. Frequent water exposure, certain medications and harsh chemicals can also weaken nails over time. Protecting nails, avoiding prolonged application of nail polish products and fake nails, in addition to moisturizing regularly can help reduce brittleness.

• Slow growth: Nails that grow unusually slowly may be affected by poor circulation, chronic inflammation, medications, or nutritional deficiencies. This is more common in toenails, which already grow slower than fingernails. Persistent slow growth can be a sign of systemic health issues that require attention.

Nail Bed and Surrounding Skin

• Redness/swelling (paronychia): This painful inflammation around the nail fold may result from eczema, chronic dermatitis, or infection (bacterial or fungal). It often appears in people whose hands are frequently wet or exposed to irritants. If untreated, paronychia can progress to chronic infection.

• Nail lifting (Onycholysis): When the nail separates from the nail bed, it may look white or yellow and can catch on clothing or cause discomfort. Psoriasis, fungal infections, chemical exposures, certain medications, and allergic contact dermatitis are common causes. Proper treatment is needed to prevent worsening or permanent damage.

• Inflamed cuticles: Cuticle or nail fold inflammation may occur in autoimmune skin disorders like lupus or dermatomyositis. The cuticles may appear red, swollen, and tender or painful to the touch. This sign often accompanies other skin or systemic symptoms and should be evaluated by a dermatologist.

Specific Skin Conditions That Show Up in the Nails

• Psoriasis: Nail psoriasis is common among people with skin psoriasis, and it can cause pitting (small dents), uneven surface changes, or discoloration. The nail may also begin to separate from the nail bed (onycholysis), which creates a white or yellowish appearance. These changes can sometimes be mistaken for fungal infections, so a dermatologist’s evaluation is important. Nail psoriasis is associated with a higher rate of psoriatic arthritis in affected patients.

• Eczema/Dermatitis: Chronic eczema around the hands and nails often leads to brittle, fragile nails that split easily. Irritation around the nail folds can cause ridging or thickening over time. Patients who frequently immerse their hands in water or use harsh soaps are especially prone to these nail changes.

• Fungal Infections: Fungal infections (onychomycosis) commonly affect toenails but can also occur in fingernails. They cause nails to become thickened, yellow, crumbly, and difficult to trim. Left untreated, fungal infections may spread to other nails or surrounding skin, making early treatment important.

• Lichen Planus: This autoimmune skin condition can also involve the nails, leading to thinning, ridging, or even permanent loss of the nail plate in severe cases. Patients may notice painful, inflamed cuticles and brittle nails that split easily. Because these changes can progress quickly, timely diagnosis is essential to prevent long-term damage.

• Skin Cancer: In rare cases, melanoma can develop in or under the nail, presenting as a brown or black streak that does not grow out like a normal bruise would. Unlike trauma-related streaks, melanoma-related changes usually appear in one nail rather than several. Any sudden pigment change in a nail should be evaluated promptly, as early detection is critical.

When to See a Dermatologist

While occasional nail ridges or white spots may not be a cause for alarm, persistent or dramatic changes may require medical attention. Consider seeing a dermatologist for the following symptoms:

• Nail changes that do not improve over time
• Pain, swelling, or bleeding around the nails
• Dark streaks or sudden changes in nail color or shape
• More than one nail (multiple nails) is affected at the same time, which may point to systemic conditions

Nail health and skin health go hand in hand. Paying attention to nail changes can help identify dermatological conditions early and prevent more serious complications. If you notice persistent discoloration, thickening, or painful changes in your nails, a dermatologist can provide both answers and treatment.

Lindsey Hunter-Ellul, MD, FAAD is a Board Certified Dermatologist and is recognized as a Texas Monthly Super Doctors Rising Star. She has years of experience in medical dermatology, skin cancer, procedural and cosmetic dermatology, treating patients of all ages and skin types. Dr. Hunter-Ellul has served on several committees for the American Academy of Dermatology, Texas Dermatological Society, and was the Physician Editor for the AAD Directions in Residency Newsletter.

Disclaimer: The contents of the Westlake Dermatology website, including text, graphics, and images, are for informational purposes only and are not intended to substitute for direct medical advice from your physician or other qualified professional.