Among the more interesting and at the same time simple ways to check for potential lung issues at home is the so-called finger test. It is a method known to both doctors and folk healers, as they have long noticed that changes on the nails often reveal more than just a lack of vitamin.

How to perform the finger test?

The test is very straightforward. Place two fingers next to each other with the nails touching – for example, the index fingers of both hands. If you see a small diamond shape between them, it means the space between the nails is normal. But if this gap disappears and the nails align perfectly next to each other, it could be a sign that the tips of the fingers have thickened.

This thickening is called clubbing of the fingers in medicine, but in layman's terms, it could be referred to as swollen fingers. This condition arises due to prolonged oxygen deficiency in the blood and often occurs in people who have lung or heart issues.

Why is the finger test important?

Lung cancer is one of the most dangerous diseases of our time. According to World Health Organization data, more than 2.2 million people worldwide are diagnosed with this type of cancer each year, with almost 40,000 cases in Europe. A unique aspect of lung cancer is that it often develops silently, without pain and without obvious signs, until the disease has progressed significantly.

The finger test offers a simple way to consider a potential issue earlier. If you notice that the characteristic diamond shape between the nails is no longer present, it could be a warning sign that something is happening in your body. This does not necessarily mean you have cancer, but it is a sign that it would be good to consult a doctor.

How do the changes on the fingers develop?

The skin and nails act as natural screens that reflect what is happening inside us. If the lungs do not receive enough oxygen over time, fluid starts to accumulate in the soft tissues of the fingers. The fingers slowly thicken, the nail bed becomes softer, the skin around the nail becomes shiny, and the nails start to curve downwards.

This process does not happen overnight. It can take months or even years. That is why people are often surprised when their doctor shows them that the change in their fingers may be related to the lungs or heart.

Recent research findings

In 2020, a British study published in the British Medical Journal revealed that 35% of lung cancer patients had visible changes on their fingers before the disease was detected through lung imaging.

In 2025, the University of Heidelberg in Germany followed 600 people with various lung conditions. They found that the finger test was reliable in 80% of patients who were later diagnosed with a chronic lung disease or cancer. Although the test itself is not a diagnosis, it can be a valuable tool for early detection.

Patient experiences: How they noticed signs at home

Brian Gemmell, a patient from the UK, in an interview with the newspaper Mirror in 2021, said that he first suspected something was wrong when he noticed this change on his fingers. Initially, he thought it was due to age or manual work, but after an examination, he was diagnosed with an early stage of lung cancer. He says: If I hadn't paid attention to my nails, I probably would have noticed the disease too late.

Similar stories have emerged in recent years on online forums and in health associations. People who noticed changes on their fingers themselves were often diagnosed at earlier stages of the disease, when treatment is more successful.

Common symptoms to watch out for

Lung cancer does not manifest equally in everyone. Some may experience symptoms early, while others only later. However, there are some warning signs worth knowing. If persistent cough (lasting more than three weeks), difficulty breathing, chest pain, recurring lung infections, or even coughing up blood occur alongside changes on the fingers, it is a clear signal that you should see a doctor.

Research shows that 70% of lung cancer patients report a prolonged cough, while 50% notice fatigue and loss of energy before diagnosis.

How folk wisdom complements modern science

Folk medicine has long recognized that nail changes reveal internal issues. Ancient herbalists said that a nail speaks more than a hundred words. If a nail was brittle, they advised consuming iron-rich foods. If it was yellowish, they recommended liver-cleansing teas. If it was curved, they often warned of weak lungs...

Although we live in an era of modern diagnostics and advanced technology, it is interesting how often these old pieces of advice align with modern medical findings.

What you can do at home

The best thing about the finger test is that you can do it yourself, without special tools and costs. Simply remember to look at your nails now and then. If you notice changes in shape or the disappearance of the diamond gap, it's a sign to pay more attention.

However, it is important to emphasize: the finger test is not a substitute for a doctor. Although it can be useful as an initial warning, diagnosis is always made by a professional. In practice, this means that an early visit to the doctor can save months or even years of life.

Why is early detection so important?

The statistics are clear: if lung cancer is detected in the early stage, the five-year survival rate is over 50%. But if the disease is diagnosed in a late stage, this number drops to less than 10%. This means that timely action truly saves lives.

A subtle sign that can save a life

Your fingers are more than just tools for typing, holding a pencil, or opening a jar. They are indicators of health and sometimes even the first herald of a serious illness. The finger test is simple, costs nothing, takes less than ten seconds, but it can give you a signal that it's time to act.

If you no longer see the small diamond shape between your nails, do not panic, but be cautious. Visit your doctor and have a conversation. It's better to know early than to wait.

In folk wisdom, there is a saying: he who listens to the body, the body will give life back to him. The finger test might be one of the simplest ways to listen to your body and possibly save your life.