One woman based in the United Kingdom is warning people of a strange finger test for lung cancer. Individuals would look for a phenomenon called ‘finger clubbing.’ Emma Norton, an oncology nurse advisor, says most people don’t know about this unusual sign, and wouldn’t know to check for it [1]. Checking your fingers for signs of clubbing is called the Schamroth window test.
When touching the nails of your index fingers together, there should be a very small space, roughly the shape of a diamond, between your cuticles. If there’s no such space, your fingers could be clubbed, which could be indicative of adverse health conditions in the body, including lung cancer.
Finger clubbing usually happens in both fingers but could happen in just one [2]. Fingers can look swollen or the nail may be curved in an almost beak-like way. People with finger clubbing, such as another woman in the UK, have received lung cancer diagnoses, but it’s not the only condition that problems with your fingernails can tell you. Here’s what you need to know about finger clubbing as well as how you can effortlessly conduct the Schamroth window test on your own at home.
What Is Finger Clubbing?
Finger clubbing (sometimes referred to as digital clubbing) is when the ends of your fingers swell up. It could present as widened fingers, a downward curve to your fingernails, or what looks like swollen tips of your fingers. This swelling is what eliminates the diamond-shaped gap between your cuticles, which is apparent during the Schamroth window test. It typically doesn’t happen overnight, instead occurring in stages.
The bed of your nails—the lighter part of your nail near your cuticles—will become softer and shinier, which is suspected to be the result of fluid buildup. The nail curve isn’t always obvious, but looking at your nails from the side can give you a better look (the curve of the nail in this way is referred to as Scarmouth’s sign). As the condition progresses, your fingers may appear larger from the fluid collection and swelling, especially at the ends of your fingers.