What you need to look for?
Some early cancers may have signs and symptoms that can be noticed, but this is not always the case. The most frequent symptoms of lung cancer are: 
- A cough that is persistent and stays the same or worsens
- Coughing up blood
- Chest discomfort that is often more severe when breathing deeply, coughing, or laughing
- Loss of appetite
- Weight loss
- Shortness of breath, tiredness or weakness, frequent lung infections, wheezing
Catching cancer early allows for a higher likelihood of successful treatment. When cancer spreads to other parts of the body, it can cause any or all of the following: 
- Bone pain (similar to back or hip pain)
- Nervous system changes (including headache, weakness, numbness in arms or legs, dizziness, balance difficulties, or seizures) from cancer spread to the brain
- Yellowing of skin and eyes (jaundice) which is caused by cancer spreading to the liver
- Swollen lymph nodes in the neck or near the collarbone
Many of these symptoms are likely to be caused by something else than lung cancer. However, if you have any of these issues, seeing your doctor as soon as possible is crucial to establish the source and treat it, if necessary. If you visit your doctor when you first develop symptoms, the disease might be detected at an earlier stage, resulting in a higher chance of successful treatment.