A woman in the United Kingdom is raising awareness about an unusual finger test that could potentially indicate lung cancer. The test involves checking for a condition known as "finger clubbing," a sign that many people are unaware of, according to Emma Norton, an oncology nurse advisor. The method used to detect this phenomenon is called the Schamroth window test.
To perform the test, press the nails of your index fingers together. Normally, a small diamond-shaped gap should appear between the cuticles. If this space is missing, it could suggest finger clubbing, which may be linked to underlying health issues, including lung cancer.
Finger clubbing typically affects both hands but can sometimes occur in just one finger. It may cause the fingers to appear swollen or the nails to curve downward, resembling a beak. While some individuals with finger clubbing, like a UK-based woman, have been diagnosed with lung cancer, it’s important to note that this condition can also signal other health problems. Below, we explain what finger clubbing is and how you can easily perform the Schamroth window test at home.
### What Is Finger Clubbing?
Finger clubbing, also known as digital clubbing, is characterized by the swelling of the fingertips. This can manifest as widened fingers, nails that curve downward, or a noticeable swelling at the tips of the fingers. The swelling eliminates the diamond-shaped gap typically seen during the Schamroth window test. The condition usually develops gradually, progressing through several stages.
In the early stages, the nail bed—the lighter area near the cuticles—may become softer and shinier, likely due to fluid buildup. While the curvature of the nails may not always be obvious, viewing them from the side can make it more apparent (a feature known as Scarmouth’s sign). As the condition advances, the fingers may appear larger, particularly at the tips, due to increased fluid retention and swelling.
