Lung cancer symptoms can vary, but certain signs warrant prompt medical evaluation, especially if they are persistent or worsening. These commonly include: a persistent cough that does not improve, potentially producing blood or rust-colored phlegm; shortness of breath or wheezing; chest pain that may intensify with deep breathing, coughing, or laughing; unexplained weight loss and loss of appetite; profound fatigue and weakness; persistent hoarseness or changes in voice; and difficulty swallowing. Other potential indicators include recurrent respiratory infections (such as pneumonia or bronchitis), swelling in the face, neck, or arms, and sudden changes in finger shape (clubbing). In some cases, headaches or dizziness may also be observed.