Finger clubbing is often a result of long-term low oxygen levels in the blood, known as hypoxemia. It’s been observed in patients with lung cancer, mesothelioma, chronic lung diseases like cystic fibrosis, and even heart conditions such as congenital heart defects. Liver and gastrointestinal diseases like Crohn’s and cirrhosis have also been linked.
To try the test yourself, press your index fingernails together and look for a diamond-shaped gap. If it’s not there, it’s worth seeing your doctor. While this isn’t a diagnosis, it’s a potentially lifesaving clue. As oncology nurse Emma Norton says, it’s a sign not to ignore. So why not take a moment, try it yourself, and share this test with others—it might just help someone catch a problem early.