Itís long been thought that lung cancer in its early stages causes few, if any, symptoms. But some researchers have found that lung cancer does cause symptoms that should prompt you to see your doctor. According to a study in the journal Thorax, 22 lung cancer patients reported 30 different symptoms before their diagnosis and recalled having new symptoms for many months. The most common symptoms were cough, breathing changes, chest or rib pain, fatigue, lethargy and weight loss. But all the patients delayed seeing their doctors because they didnít believe their symptoms were serious. A much larger study is planned to confirm the findings.