Common systemic conditions associated with nail abnormalities include psoriasis, thyroid disorders, connective tissue diseases, and nutritional deficiencies. Psoriasis is a frequent cause of nail changes such as pitting, onycholysis, and subungual hyperkeratosis, reflecting its systemic inflammatory nature NICE CG153. Thyroid dysfunction, both hypo- and hyperthyroidism, can lead to brittle nails, onycholysis, and slow nail growth due to altered metabolism and circulation NICE CG153. Connective tissue diseases like systemic lupus erythematosus and scleroderma may present with nail fold capillary changes and dystrophic nails, indicating microvascular involvement NICE CG153. Nutritional deficiencies, particularly of iron, zinc, and biotin, can cause brittle, spoon-shaped (koilonychia), or ridged nails, highlighting the importance of systemic nutritional status Cedirian et al. 2024. Additionally, chronic respiratory and cardiovascular diseases may manifest as clubbing, a notable nail abnormality linked to systemic hypoxia NICE CG153. Recognising these associations in general practice is crucial for early identification and management of underlying systemic conditions NICE CG153 Cedirian et al. 2024.
What are the common systemic conditions associated with nail abnormalities that I should be aware of in my practice?
Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.
Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX