Nail clubbing ~ A sign of possible chronic pulmonary disease include clubbing, barrel chest (the increased anterior-posterior diameter of the chest present in some patients with emphysema), and pursed lip breathing. Clubbing is enlargement of the fingertips (or toes) due to proliferation of connective tissue between the fingernail and the bone. Diagnosis is based on an increase in the profile angle of the nail as it exits the finger (to > 176°) or on an increase in the phalangeal depth ratio (to > 1—see Fig. 1: Approach to the Patient With Pulmonary Symptoms: Measuring finger clubbing.). “Sponginess” of the nail bed beneath the cuticle also suggests clubbing. Clubbing is most commonly observed in patients with lung cancer but is an important sign of chronic pulmonary disease, such as cystic fibrosis and idiopathic pulmonary fibrosis; it also occurs (but less commonly) in cyanotic heart disease, chronic infection (eg, infective endocarditis), stroke, inflammatory bowel disease, and cirrhosis. Clubbing occasionally occurs with osteoarthropathy and periostitis (primary or hereditary hypertrophic osteoarthropathy); in this instance, clubbing may be accompanied by skin changes, such as hypertrophied skin on the dorsa of the hands (pachydermoperiostosis), seborrhea, and coarse facial features. Digital clubbing can also occur as a benign hereditary abnormality that can be distinguished from pathologic clubbing by the absence of pulmonary symptoms or disease and by the presence of clubbing from an early age (by patient report). Fig. 1 Measuring finger clubbing. The ratio of the anteroposterior diameter of the finger at the nail bed (a–b) to that at the distal interphalangeal joint (c–d) is a simple measurement of finger clubbing. It can be obtained readily and reproducibly with calipers. If the ratio is > 1, clubbing is present. Finger clubbing is also characterized by loss of the normal angle at the nail bed. Signs of possible chronic pulmonary disease include clubbing, barrel chest (the increased anterior-posterior diameter of the chest present in some patients with emphysema), and pursed lip breathing. Clubbing is enlargement of the fingertips (or toes) due to proliferation of connective tissue between the fingernail and the bone. Diagnosis is based on an increase in the profile angle of the nail as it exits the finger (to > 176°) or on an increase in the phalangeal depth ratio (to > 1—see Fig. 1: Approach to the Patient With Pulmonary Symptoms: Measuring finger clubbing.). “Sponginess” of the nail bed beneath the cuticle also suggests clubbing. Clubbing is most commonly observed in patients with lung cancer but is an important sign of chronic pulmonary disease, such as cystic fibrosis and idiopathic pulmonary fibrosis; it also occurs (but less commonly) in cyanotic heart disease, chronic infection (eg, infective endocarditis), stroke, inflammatory bowel disease, and cirrhosis. Clubbing occasionally occurs with osteoarthropathy and periostitis (primary or hereditary hypertrophic osteoarthropathy); in this instance, clubbing may be accompanied by skin changes, such as hypertrophied skin on the dorsa of the hands (pachydermoperiostosis), seborrhea, and coarse facial features. Digital clubbing can also occur as a benign hereditary abnormality that can be distinguished from pathologic clubbing by the absence of pulmonary symptoms or disease and by the presence of clubbing from an early age (by patient report). Fig. 1 Measuring finger clubbing. The ratio of the anteroposterior diameter of the finger at the nail bed (a–b) to that at the distal interphalangeal joint (c–d) is a simple measurement of finger clubbing. It can be obtained readily and reproducibly with calipers. If the ratio is > 1, clubbing is present. Finger clubbing is also characterized by loss of the normal angle at the nail bed. Signs of possible chronic pulmonary disease include clubbing, barrel chest (the increased anterior-posterior diameter of the chest present in some patients with emphysema), and pursed lip breathing. Clubbing is enlargement of the fingertips (or toes) due to proliferation of connective tissue between the fingernail and the bone. Diagnosis is based on an increase in the profile angle of the nail as it exits the finger (to > 176°) or on an increase in the phalangeal depth ratio (to > 1—see Fig. 1: Approach to the Patient With Pulmonary Symptoms: Measuring finger clubbing.). “Sponginess” of the nail bed beneath the cuticle also suggests clubbing. Clubbing is most commonly observed in patients with lung cancer but is an important sign of chronic pulmonary disease, such as cystic fibrosis and idiopathic pulmonary fibrosis; it also occurs (but less commonly) in cyanotic heart disease, chronic infection (eg, infective endocarditis), stroke, inflammatory bowel disease, and cirrhosis. Clubbing occasionally occurs with osteoarthropathy and periostitis (primary or hereditary hypertrophic osteoarthropathy); in this instance, clubbing may be accompanied by skin changes, such as hypertrophied skin on the dorsa of the hands (pachydermoperiostosis), seborrhea, and coarse facial features. Digital clubbing can also occur as a benign hereditary abnormality that can be distinguished from pathologic clubbing by the absence of pulmonary symptoms or disease and by the presence of clubbing from an early age (by patient report). Fig. 1 Measuring finger clubbing. The ratio of the anteroposterior diameter of the finger at the nail bed (a–b) to that at the distal interphalangeal joint (c–d) is a simple measurement of finger clubbing. It can be obtained readily and reproducibly with calipers. If the ratio is > 1, clubbing is present. Finger clubbing is also characterized by loss of the normal angle at the nail bed.

I noticed my nails changing a few years ago.  That along with swelled ankles, Renyards Syndrom (blue fingers) and heart palpatations should have indicated lung problems to my GP but all the symptoms were never mentioned at once.  They were little complaints that added up to end stage IPF.

I keep trying to post a picture but can't for some reason.
Look up the actress Megan Fox.  Her nails are clubbed.

If you put your fingers back to back your nails should touch from cuticle to tip.
If they curve away from each other and are puffy looking see a pulmonologist.