Changes in the shape of the fingers may be a sign of lung cancer, The Mirror reports.

“Doctors have described a simple test that may help detect lung cancer at an early stage, potentially saving lives. <…> It involves placing the fingernails of the right and left hands together and pressing them against each other,” the newspaper writes, citing the Roy Castle Lung Cancer Foundation.

Normally, a small diamond-shaped gap should appear between the nails. If no gap is visible, this may indicate thickening of the fingertips, РИА Новости reports. According to The Mirror, this symptom is observed in about 35% of patients with non-small cell lung cancer and in around 4% of those with small cell lung cancer.

The article emphasizes that a positive result from this test should not be considered definitive evidence of cancer. However, specialists recommend consulting a doctor if noticeable changes in finger shape occur.

In addition to this deformity — commonly known as clubbing or Hippocratic fingers — lung cancer may also be accompanied by persistent cough, shortness of breath, fatigue and weight loss, as well as pain during breathing and coughing, the report concludes.