Lung cancer is often difficult to detect in its early stages. Common signs include chest pain, a persistent cough, coughing up blood, and nail clubbing, where the fingers become swollen and the nails curve downward. These symptoms typically begin subtly and worsen over time.

Lung cancer occurs when abnormal cells grow uncontrollably in the lung tissue and the lining of the airways. The two main types are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

It is the second most common cancer in the United States and the leading cause of cancer-related deaths among both men and women. Recognizing the early warning signs is important because it increases the chance of early detection and more effective treatment.

Early symptoms

In the early stages, lung cancer symptoms may mimic other conditions or go completely unnoticed. The lungs contain few nerve endings, which allows tumors to grow silently without causing pain or noticeable changes.

Possible early symptoms include:

  • A persistent or worsening cough

  • Chest discomfort or pain

  • Recurring respiratory infections

  • Hoarseness

  • Shortness of breath

  • Wheezing

  • Nail clubbing (swollen fingertips and curved nails)

Progressive symptoms

As lung cancer grows and spreads, symptoms often become more severe. One sign of progression is repeated lung infections, such as pneumonia or bronchitis, which may indicate obstruction from a tumor.

More advanced symptoms may include:

  • Chest pain that worsens when breathing deeply, coughing, or laughing

  • Coughing up blood

  • Difficulty breathing

  • Enlarged lymph nodes

  • Fatigue

  • Loss of appetite

  • Headaches

  • Swelling in the face

  • Trouble swallowing

  • Unexplained weight loss

  • General weakness

Some lung cancers may also lead to conditions called syndromes, which affect other systems in the body. These syndromes are sometimes reversible with proper treatment.

Examples of syndromes include:

  • Horner syndrome: Caused by tumors in the upper lungs. Symptoms include drooping of one eyelid, a smaller pupil on the same side, and decreased sweating on one side of the face.

  • Paraneoplastic syndromes: Often associated with small cell lung cancer. These may include blood clots, nervous system problems, high calcium levels in the blood (hypercalcemia), or Cushing’s syndrome caused by excess cortisol production.

  • Superior vena cava syndrome: A tumor may compress the superior vena cava, a major vein that carries blood from the upper body to the heart. This results in swelling of the face, neck, and upper chest, along with headaches and dizziness.

End-stage symptoms

When lung cancer metastasizes (spreads) to other organs, symptoms can appear throughout the body. In late stages, a person may experience a general sense of feeling unwell.

The most common sites of metastasis include the bones, brain, and liver.

Bone-related symptoms:

  • Persistent back or hip pain

  • Frequent bone fractures

Nervous system symptoms:

  • Dizziness

  • Headaches

  • Loss of coordination or balance

  • Muscle weakness

  • Numbness or tingling

  • Seizures

Liver-related symptoms:

  • Abdominal discomfort or pain

  • Yellowing of the skin and eyes (jaundice)

When to contact a healthcare provider

Because lung cancer is the leading cause of cancer-related death in the U.S., it's important to consult a healthcare provider as soon as any symptoms arise.

You should especially seek medical attention if you are in a high-risk group, such as:

  • Current or former smokers

  • People exposed to radon, asbestos, or secondhand smoke

  • Individuals with a family history of lung cancer

See a healthcare provider if you experience:

  • Chest pain that worsens with deep breathing

  • A persistent cough that is getting worse

  • Coughing up blood

  • Recurrent lung infections

While lung cancer may not always be preventable, lifestyle changes—particularly quitting smoking—can greatly reduce your risk. If you need help quitting, talk to your healthcare provider about available support.

A quick review

Lung cancer begins in the cells that line the lungs and airways. It is the second most diagnosed cancer in the United States and the top cause of cancer-related deaths in both men and women.

In the early stages, symptoms may be minimal or mistaken for less serious illnesses. These can include a chronic cough, hoarseness, wheezing, or chest pain. As the disease advances, symptoms like fatigue, weight loss, and weakness may develop. Eventually, lung cancer may spread to other parts of the body such as the bones, liver, or brain, leading to more complex symptoms.

Recognizing the warning signs and seeking early diagnosis can significantly improve treatment options and outcomes. If you have any concerning symptoms—especially if you're in a high-risk group—don't delay in speaking with a healthcare provider.

FAQs

What do nails look like with lung cancer?
Nail clubbing is common in lung cancer, particularly in individuals with low blood oxygen levels. This involves swollen, red fingertips, curved nails, and soft nail beds that appear to float.

What are some hidden signs of lung cancer?
Less obvious signs include shoulder or arm pain, eye issues, bone pain, digestive problems due to high calcium levels, balance difficulties, and unexplained changes in body weight.

Can shoulder pain indicate lung cancer?
Yes. A rare tumor called a Pancoast tumor, located at the top of the lung, can cause severe shoulder pain. This is more commonly found in non-small cell lung cancer.