Nail Disorders: Understanding Common Nail Problems and When to See a Dermatologist
Your nails are more than a cosmetic feature—they are an important part of your skin and can reveal signs of infection, inflammation, injury, and even internal health conditions. Nail disorders are common and can affect the fingernails, toenails, or the skin around the nails.
At Aglow Dermatology, we diagnose and treat a wide range of nail concerns, from fungal infections and thickened nails to nail psoriasis, nail trauma, and concerning pigment changes. Because not every nail problem is “nail fungus,” proper diagnosis is essential before treatment.
As a board-certified dermatologist with expertise in medical dermatology and skin of color, Dr. Dina Strachan carefully evaluates nail disorders to identify the true cause and recommend the most effective treatment.
What Are Nail Disorders?
Nail disorders include any condition that affects the nail plate, nail bed, cuticle, nail folds, or the skin around the nail. Because nails are an appendage of the skin—just like hair—they can reflect both skin diseases and internal health issues.
Common symptoms include:
- Thickened nails
- Brittle or splitting nails
- Nail discoloration
- White spots or dark streaks
- Nails lifting off the nail bed
- Pain around the nail
- Swelling or infection
- Ridges or dents in the nail
- Slow or abnormal nail growth
- Ingrown nails
- Nail deformities
Some nail changes are harmless. Others may signal infection, autoimmune disease, circulation problems, or even skin cancer.
Not All Nail Changes Are Nail Fungus
One of the most common misconceptions is that every nail change means fungus.
While fungal nail infections (onychomycosis) are common, many other nail disorders can look similar, including:
- Nail psoriasis
- Trauma-related nail damage
- Onycholysis
- Eczema around the nails
- Chronic irritation
- Lichen planus
- Bacterial infections
- Pigment disorders
- Nail tumors
- Skin cancer involving the nail unit
Treating the wrong condition with over-the-counter antifungal products often delays proper care.
This is why diagnosis matters.
Sometimes we perform a nail clipping, fungal culture, biopsy, or dermoscopic examination to confirm what is actually happening.
Common Nail Disorders We Treat
Fungal Nail Infections (Onychomycosis)
Fungal nail infections often cause:
- Thickened nails
- Yellow or brown discoloration
- Crumbling nails
- Distorted nail shape
- Debris under the nail
- Separation from the nail bed
Toenails are more commonly affected than fingernails.
Treatment may include:
- Prescription topical medications
- Oral antifungal medications
- Nail trimming and debridement
- Evaluation for contributing factors like athlete’s foot or diabetes
Not every thick nail is fungal, which is why confirmation is important.
Onycholysis (Nail Lifting)
Onycholysis is one of the most common nail disorders, especially in women.
This occurs when the nail separates from the nail bed underneath, creating a white or lifted appearance.
Common causes include:
- Repetitive trauma
- Aggressive manicures
- Gel and acrylic nails
- Frequent wet work
- Psoriasis
- Thyroid disease
- Fungal infection
- Irritation from nail cosmetics
Treatment depends on the cause and may include changing nail habits, treating inflammation, or addressing infection.
Nail Psoriasis
Psoriasis can affect the nails even when skin psoriasis is mild.
Common signs include:
- Pitting (small dents)
- Thickening
- Crumbling
- Oil spots (yellow discoloration)
- Onycholysis
- Subungual debris
- Nail bed separation
Nail psoriasis can be painful and may be associated with psoriatic arthritis.
Learn more on our Psoriasis Treatment page.
Paronychia and Nail Fold Infections
The skin around the nails can become inflamed or infected.
Acute Paronychia
Usually caused by bacteria after:
- Nail biting
- Picking
- Manicures
- Hangnails
- Trauma
This often causes sudden pain, redness, swelling, and sometimes pus.
Chronic Paronychia
Often caused by repeated irritation from:
- Wet work
- Cleaning products
- Frequent hand washing
- Candida yeast
- Inflammation
This is common in healthcare workers, food workers, and people whose hands stay wet often.
Felons
A felon is a deeper, painful infection of the fingertip pulp that may require urgent treatment.
Inflammation around the nail can also disrupt future nail growth.
Trauma-Related Nail Changes
Repeated trauma from shoes, sports, habits, or nail picking can lead to:
- Thickened nails
- Dark nails (subungal hematoma)
- Split nails
- Nail ridging
- Permanent nail deformity
- Onycholysis
- Ingrown nails
Tight footwear is a major cause of toenail problems.
This is especially common in runners, dancers, and people who wear narrow shoes.
Dark Lines in the Nail (Melanonychia Striata)
A dark stripe running lengthwise in the nail is called longitudinal melanonychia.
This is especially common in people with darker skin tones and is often benign.
However, it can also be a sign of nail melanoma, including acral lentiginous melanoma.
Warning signs include:
- A wide or rapidly changing band
- Irregular borders
- Multiple colors
- Pigment spreading onto surrounding skin
- One single dark band that is new
- Pain, bleeding, or nail destruction
These changes should be evaluated by a dermatologist promptly.
This is especially important in patients with skin of color, where pigment bands may be common—but melanoma must not be missed.
Learn more on our Skin Cancer.
Warts Under the Nail
Warts can develop around or underneath the nail.
- Pain
- Distortion of nail growth
- Thickened skin
- Cosmetic concerns
These may cause:
Periungual warts can be stubborn and often require professional treatment rather than home remedies.
See our Wart Treatment page.
Nail Cancers and Tumors
Skin cancer can occur in or around the nail unit.
This may include:
- Squamous cell carcinoma
- Melanoma
- Glomus tumors
- Other growths under the nail
Signs include:
- Persistent pain
- Bleeding
- Nail destruction
- A dark streak
- A non-healing growth
- A “wart” that does not improve
Any persistent abnormality should be evaluated.
Nail Changes from Skin Conditions
Several skin diseases affect the nails, including:
- Psoriasis
- Lichen planus
- Alopecia areata
- Eczema
- Lupus
- Dermatomyositis
Sometimes nail changes appear before the skin diagnosis is obvious.
Because dermatologists specialize in skin, hair, and nails, we are uniquely trained to recognize these patterns.
Nail Signs of Illness
Sometimes nails reflect internal health conditions.
Examples include:
- Clubbing (lung disease, heart disease)
- Spoon nails (iron deficiency)
- Beau’s lines (illness or stress)
- Terry’s nails (liver disease)
- Splinter hemorrhages
- Pale nails (anemia)
- Yellow nails
- Brittle nails from thyroid disease
Patients often search for “nail signs of illness” or “nail signs of vitamin deficiency”—and sometimes those concerns are valid.
Your nails can provide clues, but diagnosis requires context.
Nail Splitting, Dry Nails, and Brittle Nails
Nails can become dry, split, and fragile from:
- Frequent hand washing
- Harsh soaps
- Acetone removers
- Aging
- Water exposure
- Nutritional deficiencies
- Thyroid disorders
- Iron deficiency
- Repetitive trauma
Treatment may include:
- Barrier repair
- Cuticle care
- Moisturizing creams and oils
- Reducing irritants
- Treating underlying medical conditions
Healthy nails often start with healthy skin care habits.
Nail Biting and Body-Focused Repetitive Behaviors (BFRBs)
Nail biting, cuticle picking, and repetitive nail trauma can cause:
- Infection
- Chronic inflammation
- Nail deformity
- Pain
- Permanent nail changes
These behaviors are often part of body-focused repetitive behaviors (BFRBs), not simply “bad habits.”
Dr. Dina Strachan has expertise in BFRBs and helps patients manage both the physical damage and the behavioral pattern behind it.
Visit our BFRB Treatment page to learn more.
How Footwear and Nail Cosmetics Affect Nails
Your daily habits matter.
Common contributors include:
- Tight shoes
- High heels
- Repetitive friction
- Acrylic nails
- Gel manicures
- Nail glue
- Harsh removers
- Cuticle cutting
- Excessive filing
Even beauty routines can cause nail growth problems.
We help patients identify these triggers and create safer nail care routines.
How Dermatologists Diagnose Nail Disorders
A proper nail evaluation includes:
- Medical history
- Medications
- Skin conditions
- Nail habits
- Occupation and hand exposure
- Footwear habits
- Cosmetic products
- Family history
- Physical examination of skin, scalp, and nails
Sometimes diagnosis requires:
- Nail clipping
- Fungal testing
- Culture
- Dermoscopy
- Biopsy
- Blood work
Because nails often reflect bigger health patterns, diagnosis should not be rushed.
When to See a Dermatologist for Nail Problems
You should schedule an evaluation if you have:
- Thickened nails
- Painful nails
- Dark streaks
- Nail lifting
- Recurrent infections
- Bleeding around the nail
- Nail changes that are worsening
- A “fungus” that won’t improve
- Nail growth problems
- New pigment bands
- Chronic brittle or splitting nails
Early diagnosis can prevent permanent damage.
Nail Disorder Treatment in NYC
At Aglow Dermatology, we diagnose and treat nail disorders in patients of all skin tones and ages.
Whether you have nail fungus, nail psoriasis, painful paronychia, melanonychia, or unexplained nail changes, we focus on finding the real cause—not just guessing.
We provide expert dermatologic care for nails, skin, hair, and scalp from our Manhattan office near Grand Central.
Frequently Asked Questions About Nail Disorders
No. Thick nails can also be caused by trauma, psoriasis, aging, eczema, or chronic pressure from shoes.
This is called onycholysis and can result from trauma, psoriasis, thyroid disease, fungal infection, or nail cosmetics.
Sometimes. Many are harmless, especially in darker skin tones, but some may be signs of melanoma and should be evaluated.
Yes. Some patients have nail psoriasis before obvious skin psoriasis develops.
Repeated trauma, wet work, nail biting, and chronic irritation commonly cause paronychia.
Yes. Dermatologists can help treat the skin damage and support management of body-focused repetitive behaviors.
Schedule an Appointment for Scalp Problems
Schedule Your Nail Evaluation
If your nails are changing, painful, discolored, or simply not improving, don’t assume it is fungus.
Accurate diagnosis matters.
Schedule an appointment with Aglow Dermatology for expert evaluation and treatment of nail disorders in NYC.