Whether a nodule 6x4mm is serious or not needs to be judged according to the nature of the nodule. If the nodule is benign, no special treatment is required, while if it is malignant, early surgical removal is necessary. Common nodules include thyroid nodules, lung nodules, breast nodules, etc. Although 6x4mm nodules are small in size, whether they are serious or not needs to be determined by further examination. If the nodule is benign and does not affect normal life, it is not serious and only needs to be reviewed regularly to monitor the status of the nodule. Meanwhile, if the nodule is found to increase rapidly in size in a short period of time and affects normal life, surgical removal is recommended. If the examination suggests malignant nodules, they are mostly malignant tumors, and in order to avoid metastasis and spread of cancer cells, surgical removal should be arranged as soon as possible. If 6x4mm size nodules are found in the examination, a professional physician is needed to judge whether it is serious or not, and then carry out corresponding treatment.