Side effects such as arteriovenous fistula, blocker dislodgement, thrombosis, and residual shunt can occur with foramen ovale occlusion blockage, but the chances of side effects are low and there is no need to worry too much about them. Foramen ovale occlusion is now mainly treated by interventional occlusion. If vascular damage is caused by puncturing the vessel, arteriovenous fistula can occur after the operation; strenuous activities after implantation of the blocker can increase the risk of dislodgement; the blocker, as a foreign body, can induce coagulation reaction after entering the body and form thrombus; failure to cover the blocker completely or displacement can cause residual blood shunt. The chances of the above side effects are small, so there is no need to be overly anxious, and the treatment can be carried out in accordance with the doctor’s instructions. However, in order to prevent side effects from affecting the efficacy of the treatment or causing poor prognosis, postoperative care and review should be carried out in accordance with the doctor’s instructions after the surgery.