What is the cause of digital clubbing (clubbing of the fingers)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 19, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Digital clubbing is primarily caused by underlying health issues, most commonly lung diseases, heart conditions, inflammatory bowel diseases, liver cirrhosis, and certain infections, which lead to chronic hypoxia or inflammation. The exact mechanism behind clubbing isn't fully understood, but it likely involves increased blood flow to the fingertips and changes in the connective tissue due to growth factors released in response to chronic hypoxia or inflammation 1. When digital clubbing is observed, medical evaluation is necessary to identify the underlying cause, which may include conditions such as cystic fibrosis, congenital or acquired immunodeficiency, congenital heart disease, bronchopulmonary dysplasia, pulmonary infection, primary ciliary dyskinesia presenting with newborn respiratory distress 1. Some key points to consider in the evaluation of digital clubbing include:

  • Respiratory signs such as resting tachypnea, adventitious sounds, retractions, digital clubbing, failure to thrive, or respiratory failure
  • Hypoxemia
  • Diffuse abnormalities on chest X-ray (CXR) or computed tomography (CT) scan Diagnosis involves physical examination and may require additional tests like chest X-rays, pulmonary function tests, or blood work depending on suspected causes. Treatment focuses on addressing the underlying condition rather than the clubbing itself, and if the primary disease is successfully treated, digital clubbing may sometimes reverse, though this isn't always the case. It is essential to note that digital clubbing can be a symptom of a serious underlying condition, and prompt medical evaluation is necessary to determine the cause and provide appropriate treatment.

From the Research

Causes of Digital Clubbing

  • Digital clubbing can be associated with various underlying conditions, including chronic obstructive pulmonary disease (COPD) and lung cancer 2.
  • It is also seen in patients with fibrotic interstitial lung diseases, such as idiopathic pulmonary fibrosis (IPF) 3.
  • In patients with cystic fibrosis, digital clubbing can be reversible after successful treatment of the underlying pathology, such as lung transplantation or highly effective CFTR modulator therapy 4.
  • Nail disorders, including digital clubbing, can provide important clues to underlying systemic diseases, highlighting the importance of considering nail changes in the diagnosis and management of patients 5.
  • Digital clubbing has been observed in patients with significant weight loss, pulmonary masses, and other serious conditions, emphasizing the need for thorough evaluation and diagnosis 2, 3.

Associated Conditions

  • COPD 2
  • Lung cancer 2
  • Fibrotic interstitial lung diseases, including IPF 3
  • Cystic fibrosis 4
  • Systemic diseases, such as those affecting the cardiovascular, respiratory, or gastrointestinal systems 5

Assessment and Diagnosis

  • Various methods can be used to assess digital clubbing, including the phalangeal depth ratio, digital index, and Schamroth sign test 3.
  • However, these methods may have poor correlation, and further studies are needed to develop reliable and effective assessment tools 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[Nail Clubbing].

Revue medicale suisse, 2024

Research

Impact of highly effective CFTR modulator therapy on digital clubbing in patients with cystic fibrosis.

Journal of cystic fibrosis : official journal of the European Cystic Fibrosis Society, 2022

Research

Nail disorders as clues to systemic disease.

Clinics in dermatology, 2024

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.