Eight signs of lung cancer to look out for as Pope Leo makes first public appearance after surgery

Pope Leo XIV has been diagnosed with lung adenocarcinoma, prompting renewed attention to eight symptoms associated with the disease, including a persistent cough, unexplained weight loss and coughing up blood.

The 71-year-old pontiff underwent surgery to remove the lower lobe of his right lung after doctors discovered a nodule during routine medical checks. The Vatican confirmed that the procedure was successful, with the operation lasting approximately 90 minutes.

According to the CDC, Lung adenocarcinoma is the most common type of lung cancer in the United States, accounting for approximately 40% to 45% of all lung cancer cases.

The organization lists several warning signs people should be aware of, although experiencing them does not necessarily mean someone has cancer.

Surgeons removed the lower lobe of Pope Leo XIV's right lung during a procedure that lasted approximately 90 minutes. (Photo by Simone Risoluti - Vatican Media via Vatican Pool/Getty Images)

What are the eight symptoms of lung cancer?

A cough lasting three weeks or longer is one symptom to look out for, particularly if there has been a noticeable change in an existing cough.

Persistent chest or shoulder pain is another potential warning sign. The discomfort may feel dull and ongoing, becoming worse when breathing deeply, coughing or laughing.

Repeated chest infections, or an infection that does not clear up, can also be associated with lung cancer. People may experience two or more infections within a relatively short period without an obvious explanation.

Other symptoms include unexplained breathlessness and wheezing, which can become noticeable during everyday activities such as climbing stairs or walking to the store.

Coughing up blood is another sign that warrants attention, even when only a small amount is present or blood appears in mucus.

The remaining three symptoms are loss of appetite, unintended weight loss and persistent fatigue.

Someone experiencing a loss of appetite may feel less interested in food or become full after eating only a small amount. Unexplained weight loss means losing a noticeable amount without deliberately changing eating habits or exercising more.

Fatigue can also be associated with the disease, particularly when exhaustion persists despite getting enough sleep or resting during the day.

Pope Leo XIV, 71, was diagnosed with lung adenocarcinoma after doctors discovered a nodule in his lung. (Photo by David Ramos/Getty Images)

Can you lung cancer without smoking?

Although smoking is a major risk factor for lung cancer, people who have never smoked can also develop the disease.

Pope Leo is not known to have smoked. His diagnosis highlights that lung cancer is not exclusive to people with a history of tobacco use.

Lung adenocarcinoma develops in cells that produce mucus and is often found in the outer areas of the lungs. It is also the most common type of lung cancer diagnosed in non-smokers.

Lung adenocarcinoma is the most common type of non-small cell lung cancer, according to Macmillan Cancer Support. (Getty Stock Image)

What happens after a lung cancer diagnosis?

The Vatican said doctors had confirmed the diagnosis during surgery, after earlier tests had raised suspicions about the lung nodule.

In a medical statement, officials said: "The procedure was completed successfully, within the expected timeframe and as planned."

The Vatican has not disclosed the stage of the Pope's cancer. Further tests were being carried out, and chemotherapy was reportedly not under discussion at the time of the earlier update.

Treatment depends on the stage of the disease. Surgery to remove the affected area may be used in early-stage cases, while radiation therapy is another possible treatment.

Survival rates also vary considerably depending on how advanced the cancer is when diagnosed.

According to official guidelines from the U.S. Centers for Disease Control and Prevention (CDC), lung cancer often develops silently, with most individuals showing no physical warning signs until the disease has already reached an advanced stage. When symptoms do manifest, they typically present as respiratory issues that are easily mistaken for less severe illnesses.

Coughing blood is one of the symptoms associated with lung cancer. (Getty Stock Image)

The CDC urges individuals to consult a physician if they experience a persistent or worsening cough, unexplained chest pain, shortness of breath, wheezing, or if they begin coughing up blood.

Systemic changes such as chronic fatigue, unexplained weight loss, and recurring bouts of lung infections like pneumonia should also prompt immediate medical evaluation, as early detection remains a critical factor in improving patient survival rates