The generic name of Euthyrox is Levothyroxine Sodium Tablet. Feeling neck swelling after taking Levothyroxine Sodium Tablet treatment may be caused by goiter, thyroid nodules and other conditions, which need to be treated under the guidance of the doctor, such as medication, surgical treatment, and regular review and so on. Taking levothyroxine sodium tablets does not cause neck swelling, neck swelling may be caused by goiter, thyroid nodules and other factors. 1. Goiter: continue to take levothyroxine sodium tablets as prescribed by the doctor. If the goiter is large and presses on the neighboring organs, it may produce compression symptoms, such as difficulty in breathing, difficulty in swallowing, etc. Surgery should be considered. 2. Thyroid nodules: also need to continue to follow the doctor’s advice to take levothyroxine sodium tablets treatment, thyroid nodules larger to produce pressure symptoms or diagnosis of malignant thyroid nodules need to be considered for surgical resection; if the nodules are not large and benign when regular review can be. If you experience swelling of the neck after taking levothyroxine sodium tablets, it is recommended to go to the hospital for consultation.