What lung disease cause clubbing nails and can it be a sign of respiratory acidosis?

Clubbing: describes the bulbous, clublike deformation of the distal portion of the fingers and toes resulting from connective-tissue proliferation.Clubbing may be hereditary , ie, primary hypertrophic osteoarthropathy, but, more often, it is acquired and is associated with a number of infectious, inflammatory, neoplastic, and vascular disorders. it may occur with several lung diseases . Ref:Medscape

Clubbing: Lung causes may include: complicated TB, Sarcoidosis, Mesothelioma of pleura, lung cancer (non-small-cell), interstitial dz’s and conditions that cause pus to build up in lung structures. REF: https://en.wikipedia.org/wiki/Nail_clubbing