Jelly sputum is not a sign of lung cancer.
Jelly sputum is caused by crystallization of eosinophils, which is mostly considered to be caused by infection of lungs by Klebsiella pneumoniae, and it is rare for lung cancer patients to have jelly sputum.
Besides, lung cancer patients usually do not have obvious discomfort in the early stage, and only some of them may suffer from emaciation, coughing up blood, coughing and so on, but they will not have jelly sputum, so it can be seen that the appearance of jelly sputum is not a precursor of lung cancer.
If the occurrence of jelly sputum is accompanied by coughing up blood and sputum for a long period of time, it is necessary to improve the lung function, sputum culture, chest X-ray, lung CT and other examinations in a timely manner.