Clubbing of the fingers or toes refers to certain physical changes to your fingernails or toenails that result from an underlying medical condition. These changes can include:

  • widening and increased roundness of your nails
  • increased angle between your cuticles and nails
  • downward curving of your nails
  • softening of your nail beds, which makes your nails seem like they’re floating
  • enlarging or bulging of the tip of your fingers or toes, which may be accompanied by redness or warmth

These changes can develop in a matter of weeks or years, depending on the cause. They can be the result a variety of underlying medical conditions, many of which are serious. If you develop clubbing of your fingers or toes, make an appointment with your doctor.

It’s not completely understood why clubbing occurs, but certain conditions are known to activate components in the bloodstream. This activation plays a role in changing the nail bed.

Nail widening that characterizes clubbing happens when the tissue under your nail plate becomes thicker. This can be triggered by a number of conditions throughout the body. For example, clubbing often results from lung issues, such as:

  • lung cancer, a disease that develops when you have abnormal lung cells that grow out of control
  • cystic fibrosis, a genetic condition that affects how salt and water are moved throughout the body and creates thick secretions within the lungs and other organs
  • pulmonary fibrosis, a condition that occurs when your lung tissue becomes thick and scarred, often for unknown reasons
  • bronchiectasis, a condition that occurs when your airways become widened and scarred due to infection or other factors that prevent your lungs from expelling mucus
  • asbestosis, a disease that develops when you inhale asbestos fibers that scar your lung tissue

Clubbing can also be a symptom of several other diseases and disorders, such as:

To treat clubbing, your doctor will need to address the underlying cause of your symptoms. Your recommended treatment plan will depend on your diagnosis. For example, your doctor may prescribe:

In rare cases, your doctor may recommend a lung transplant to treat serious lung disease.

The only way to prevent clubbing is by taking steps to prevent and manage the underlying conditions that cause it. For example, you can:

  • reduce your risk of lung cancer by avoiding tobacco smoke and limiting your exposure to toxins in the workplace
  • lower your chances of developing bronchiectasis by getting vaccinated against measles and whooping cough, seeking prompt treatment for lung infections, and limiting your contact with tobacco smoke and other toxins
  • prevent asbestosis by using protective equipment when you’re working in an industry such as construction where you might be exposed to asbestos

If you’ve been diagnosed with a lung disease, follow your doctor’s recommended treatment plan. That may help you maintain your blood oxygen levels and prevent clubbing.

Most of the underlying conditions that cause clubbing are serious, and early diagnosis and treatment may improve your outlook. Make an appointment with your doctor if you notice any signs of clubbing of your toes or fingers.

In some cases, your toes or fingers may return to their normal shape once your underlying medical condition has been treated. Some of the conditions that cause clubbing can be cured, some are chronic but manageable, and some are harder to treat.