I called the dr this last week due to coughing up blood. he performed a chest x-ray and found a nodule on my left lung base. he ordered a cat scan. how worried should i be that this is cancer? both of my grandfathers passed from lung cancer?

Your doctor is following the appropriate evaluation and would urge you to pursue the recommendations. The "nodule", if ominous, can be best handled if appropriate intervention is completed ASAP. Work closely with your doctor. Best luck.

While early cancer cannot be ruled out, there are many other conditions including bronchitis and/or pneumonia much more frequent and likely that may cause similar symptoms. In case the CT scan confirms the presence of a nodule surveillance scans will be needed.