Finger clubbing is a change in the appearance and feel of the fingernails or toenails. The nail widens and bulges at the cuticle.
“The finger looks kind of like an upside-down spoon shape, rather than having a natural concave curve at the cuticle,” says Bryan Andrew Faller, MD, director of cancer research at Missouri Baptist Medical Center in St. Louis.
- Feel warm
- Get soft and spongy
- Turn red
- May feel painful
With finger clubbing in early-stage lung cancer, the nail changes occur so slowly that they aren’t noticeable. “With a lot of patients I meet with lung cancer, I look at their fingers and they have [finger clubbing] and they didn’t even know it,” says Dr. Faller.
Finger clubbing isn’t dangerous. It’s mainly a cosmetic issue, and the nails should return to their original size and shape once the cancer is treated, says Faller, although occasionally finger clubbing remains after the cancer is cured.
Finger clubbing is not always caused by lung cancer — it can occur alongside many other conditions, such as celiac disease or Graves’ disease. Speak with your doctor if you think you have finger clubbing to determine the cause.