Insomnia throughout the night after taking Synthroid may be caused by the side effects of the drug, because Synthroid, as an antidepressant drug, has a very good effect, can selectively block 5-hydroxytryptamine reuptake, so it may cause symptoms such as excitement, anxiety, irritability, and other symptoms, especially after taking the drug with insomnia as a side effect. However, if the symptoms of insomnia are present from the beginning, it may also be a sleep disorder in itself, and these two causes should be analyzed on a case-by-case basis. If the problem of sleep disorder is present from the beginning, such as insomnia, dreaminess or drowsiness, it may be caused by problems such as depression, as these mental illnesses are prone to sleep disorder. If the problem of sleeplessness occurs only after taking medication, it may be a side effect of the medication, which can be treated with anti-anxiety or sedative-hypnotic medications, such as zopiclone or eszopiclone, alprazolam, which can help to treat the problem of insomnia.