Thyroid 4a generally refers to thyroid nodule 4a, which is graded under thyroid ultrasound. Performing thyroid nodule puncture may cause pain, bleeding, wound infection and other adverse conditions. Thyroid nodule puncture is an invasive test, which may cause pain and discomfort at the examination site; and some patients after thyroid puncture may also experience localized bleeding and hematoma at the puncture site, which may cause respiratory difficulties in severe cases; and if the puncture is not properly cared for, it may also cause wound infection. Although thyroid nodule puncture may cause the above adverse conditions, thyroid nodule 4a is a suspected malignant nodule, indicating that there is a possibility of malignancy, for this need to clarify the nature of the nodule, it is recommended to follow the doctor’s instructions for examination and treatment. Patients who need to undergo thyroid nodule puncture are advised to actively cooperate with their doctors.