What causes nails to stop growing?

What Can Cause Nails to Stop Growing

Nails do not truly "stop" growing in most cases, but rather slow their growth rate significantly due to aging, with growth declining from approximately 0.123 mm/day at age 32 to 0.095 mm/day by age 67. 1

Primary Causes of Apparent Nail Growth Cessation

Age-Related Slowing

• Normal aging is the most common cause of dramatically slowed nail growth, as the nail matrix's ability to produce smooth, rapidly-growing nails diminishes over time 2, 1
• Fingernails normally grow 2-3 mm per month, requiring 6-9 months for complete replacement, but this rate decreases substantially with advancing age 3
• Nails grow even more slowly in older adults compared to younger individuals, making age-related changes the primary consideration when evaluating perceived growth cessation 4

Nail Matrix Damage

• Direct cytotoxic damage to the nail matrix from chemotherapy agents (particularly taxanes) can severely impair or halt nail production 5
• Chronic trauma to the nail matrix causes permanent damage that prevents normal nail plate formation 5, 2
• Inflammatory conditions like lichen planus and psoriasis damage the nail matrix, causing thinning, longitudinal ridging, and dramatically slowed growth 2

Severe Infections

• Chronic paronychia (infection and inflammation in the nail matrix area) leads to proximal nail dystrophy with impaired growth, particularly in patients with chronic moisture exposure 2
• Fungal infections (onychomycosis) cause nail plate thickening and dystrophy that can make growth appear arrested, though the matrix continues producing abnormal nail tissue 5, 2
• Bacterial infections, particularly Pseudomonas, can damage the nail bed and impair normal growth patterns 5, 6

Secondary Contributing Factors

Medication-Induced Changes

• Taxane chemotherapy causes dose-related nail changes that increase with cumulative exposure, with weekly regimens showing higher incidence of severe nail damage 5
• The integrity of peripheral nerves is substantial for developing nail alterations with taxanes, suggesting a drug-induced neurotropic effect that impairs growth 5
• mTOR inhibitors, EGFR inhibitors, and MEK inhibitors can all cause nail lesions that become evident after several weeks due to the slow growth rate 5

Nutritional Deficiencies

• Virtually every nutritional deficiency can affect nail growth in some manner, though specific evidence for complete growth cessation is limited 3
• Severe malnutrition states can dramatically slow or appear to halt nail production 3
• However, no evidence supports vitamin supplementation for improving nail health in well-nourished patients 7

Critical Diagnostic Approach

Essential Clinical Evaluation

• Examine all 20 nails systematically to distinguish localized trauma from systemic causes 4
• Assess for signs of infection: green discoloration (Pseudomonas), thickening and friability (fungal), or purulent discharge (bacterial abscess) 5, 2, 6
• Look for inflammatory signs: vertical ridging with skin lesions (psoriasis/lichen planus), proximal nail fold inflammation (chronic paronychia), or nail plate thinning 2

Laboratory Confirmation When Indicated

• Direct microscopy with potassium hydroxide (KOH) preparation and fungal culture on Sabouraud's glucose agar are essential if fungal infection is suspected, as clinical appearance alone is insufficient 2, 8
• Calcofluor white staining significantly enhances visualization of fungal elements compared to standard KOH preparation 8
• Bacterial culture should be obtained if green discoloration suggests Pseudomonas infection 8, 6

Common Pitfalls to Avoid

• Never assume complete growth cessation without examining the proximal nail fold and matrix area - apparent cessation may actually be severe slowing or production of extremely abnormal nail plate 4
• Do not diagnose fungal infection based on appearance alone, as 50% of nail dystrophy cases are non-fungal despite similar clinical presentation 8
• Avoid attributing slowed growth to nutritional deficiency in well-nourished patients, as supplementation (except biotin for brittle nails) lacks supporting evidence 7
• Recognize that nail changes from chemotherapy are dose-related and may require treatment modification rather than topical interventions alone 5