Clubbing is changes in the areas under and around the toenails and fingernails, and in the nails themselves that may occur with some disorders.

Clubbing

Common symptoms of clubbing:

• The nail beds soften. The nails may seem to "float" instead of being firmly attached.
• The angle that the nail makes with its cuticle increases.
• The last part of the finger may seem large or bulging. It may also be warm and red.
• The nail curves downward, similar to the shape of the round part of an upside-down spoon.

Clubbing can develop quickly, often within weeks. It also can go away quickly when its cause is treated.

Lung cancer is the most common cause of clubbing. Clubbing often occurs in heart and lung diseases that reduce the amount of oxygen in the blood, such as:

• Heart defects that are present at birth (congenital)
• Chronic lung infections that occur in people with bronchiectasis,cystic fibrosis, or lung abscess
• Infection of the lining of the heart chambers and heart valves (infectious endocarditis), which can be caused by bacteria, fungi, or other infectious substances
• Lung disorders in which the deep lung tissues become swollen and then scarred (interstitial lung disease)

Other causes of clubbing:

• Celiac disease
• Cirrhosis of the liver and other liver diseases
• Dysentery
• Graves disease
• Overactive thyroid gland
• Other types of cancer, including liver, gastrointestinal, Hodgkin's lymphoma

If you notice clubbing, call your health care provider.

A person with clubbing usually has symptoms of another condition. Diagnosing that condition is based on:

• Family history
• Medical history
• Physical exam that looks at the lungs and chest

Medical history questions may include:

• Do you have any breathing difficulty?
• Does clubbing affect the fingers, toes, or both?
• Is it becoming more noticeable?
• Is the skin ever bluish-colored?
• What other symptoms do you have?
• When did you first notice this?

The following tests may be done:

• Arterial blood gas
• Chest CT scan
• Chest x-ray
• Echocardiogram
• EKG
• Pulmonary function tests

There is no treatment for the clubbing itself. The cause of clubbing can be treated, however.

Murray JF, Schraufnagel DE. History and physical examinations. In: Mason RJ, Broaddus VC, Martin TR, et al. Murray & Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier;2010:chap 17.