A simple test that involves making a small diamond window with your fingers can help you to see the warning signs of a serious health condition, including lung cancer and heart disease, doctors say.

Imagine being able to perform a quick test with your own hands that might give you an early warning sign of a serious health condition.

The Schamroth window test, a simple and non-invasive finger check, has been recognized by medical professionals as a potential indicator of finger clubbing, a condition linked to lung cancer, heart disease, and other serious illnesses.

Let’s discover how the Schamroth works, and what its results could mean for your health.

Finger clubbing
The Schamroth window test is a simple technique used to check for finger clubbing, also known as digital clubbing, a condition that Medscape explains affects the shape of the fingers and fingernails.

Finger clubbing typically takes years to develop and happens in stages. According to Cancer Research UK, if finger clubbing is present:

The nail bed feels warm and the skin around the nail look shiny.
The ends of the fingers look larger, giving the ‘clubbed’ appearance.
There’s a softening of the nail bed.
There’s an increased curvature of the nails – nails curve downward and look like spoons.
Nail beds feel spongy.
The exact cause of finger clubbing is not entirely understood, but Very Well Health reports that it’s believed to “happen because of long-term low levels of oxygen in the blood, known as hypoxemia.”

Potential conditions
Finger clubbing has been associated with several serious conditions, including:

Lung cancer: Studies show that 35% of people with non-small cell lung cancer experience finger clubbing, while it is less common (around 4%) in small cell lung cancer cases.

Mesothelioma: This rare cancer, often caused by asbestos exposure, affects the lining of the lungs and chest. Finger clubbing has been observed in many mesothelioma patients.