Finger Clubbing and Lung Cancer

A change in the appearance of the fingernails or toenails can be a sign of serious illness. One such change is called clubbing. Clubbing can be a sign that something is wrong with your heart or lungs, so it is important to see a doctor if it happens to you.^1,2

What is finger clubbing?

Finger clubbing is when your fingernails or toenails start to curve downward over the tip of the fingers or toes. This condition is also called nail clubbing or digital clubbing.^2,3

Clubbing causes the nail to look like the round part of an upside-down spoon. The tissue under the nail softens, and the nail may seem like it is not firmly attached.²

Your fingertips might also look bigger or rounded. Some people with clubbing will have redness or swelling around the nail.²

Clubbing can develop within a few weeks. Sometimes, people with clubbing will have joint swelling and pain. While there is no treatment specifically for finger clubbing, it may go away when the underlying illness is treated.^2,4

What causes clubbing?

In 80 percent of cases, clubbing is caused by lung or heart problems. The most common cause of nail clubbing in adults is lung cancer.

However, clubbing is only seen in five to fifteen percent of people diagnosed with lung cancer. Clubbing is also linked to other heart and lung diseases that decrease oxygen levels in the blood.^1,3

In five percent of cases, nail clubbing is due to gastrointestinal (GI) problems. For some people, nail clubbing is inherited and is not a sign of illness.^1,3

Conditions that can cause clubbing include:^2,3

• Lung cancer
• Heart defects present at birth
• Chronic lung infections (bronchiectasis, lung abscess, cystic fibrosis)
• Infectious endocarditis (a type of heart infection)
• Interstitial lung disease (a disease that causes scarring of the lung tissue)
• Celiac disease and inflammatory bowel disease
• Cirrhosis and other liver diseases
• Thyroid problems
• Hodgkin lymphoma
• Other types of cancer (liver, gastrointestinal, throat, and esophagus)
• Laxative overuse

Not all people with nail clubbing have an underlying medical problem. In addition, many people with conditions like lung cancer do not have nail clubbing.^1,3

The link between clubbing and lung cancer

Not everyone with nail clubbing has lung cancer. But if you notice this change in your nails along with other symptoms like a persistent cough, breathing difficulties, or weight loss, it is essential to see a doctor. Early detection and treatment can make a big difference in managing lung cancer.^2,5

Evaluation of clubbing

If you notice clubbing of your fingernails or toenails, it could be a sign of lung cancer.²

Evaluation of nail clubbing typically involves a thorough medical history and physical examination of the lungs and chest. Your doctor may recommend other tests, including:²

• Blood tests
• Chest X-ray
• Chest CT scan
• Echocardiogram (ECG)
• Pulmonary function tests
• Early detection of lung cancer

Lung cancer is more treatable when it is found early. Lung cancer does not usually cause symptoms in the early stages. If symptoms do occur, they may include:⁵

• A cough that is getting worse or does not go away
• Coughing up blood
• Difficulty breathing
• Wheezing
• Chest pain
• Feeling tired all the time
• Weight loss

If you notice nail clubbing, it could be a sign of lung cancer. Talk to your doctor about being checked for lung cancer or other medical problems.