The human body is full of small signs that can reveal when something isn’t right, though many of us tend to overlook them. We often assume mild symptoms will pass on their own — after all, sometimes a simple headache really is just that.
But when it comes to clubbing, experts say it’s not something you should ignore, as it can point to serious health issues developing beneath the surface.
In some cases, the nails may also look shiny or distorted, giving the fingers a bulbous shape that feels strange to the touch. These physical changes often develop gradually over time rather than all at once.
Doctors note that this condition is one of the clearest external signs that something deeper in the body could be wrong, especially with the heart or lungs.
While the changes may not be painful, they can indicate something happening internally — and catching it early can make a big difference in diagnosis and treatment.
Although nail clubbing might seem harmless, doctors emphasize that it can sometimes signal the presence of a serious illness, including lung cancer or other life-threatening diseases.
As stated by the Cleveland Clinic: “Nail clubbing is most often associated with diseases of the heart and lungs, like lung cancer, lung infections, interstitial lung disease, cystic fibrosis or cardiovascular disease.”
Doctors also warn that dark vertical lines under the nails should not be ignored either, as these could indicate additional underlying health concerns that need further investigation.
“This can be a sign of liver disease, lung conditions and gastrointestinal problems.”
Dr. Huang added that, although rare, dark streaks or lines forming beneath the nail bed can sometimes point to melanoma, a serious form of skin cancer that requires immediate medical attention.
A study from 2012 led by Dr. Malay Sarkar, a lung cancer specialist based in India, found that lung cancer is the leading cause of nail clubbing, accounting for nearly 90 percent of reported cases.
However, researchers note that the condition only affects between five and 15 percent of people with lung cancer, meaning it’s not always present — but when it is, it’s an important warning sign not to overlook.
