Stellate ganglion block treatments are considered minimally invasive and safe, coming with a few risks that are rare. However, the injections are administered in a riskier area in order to actually provide the noted benefits, so they should be administered with the use of ultrasound or fluoroscopic guidance to provide accurate imaging to avoid the syringes from hitting anywhere that they aren’t supposed to touch. An experienced and qualified physician will minimize any side effects or more serious risks as much as possible, making this a very safe procedure when performed by a qualified professional. Some common but temporary side effects include: - Nasal stuffiness - Difficulty swallowing - Watery eyes - Drooping eyelids - Bruising or soreness where the SGB was injected - Bloodshot eyes - Tingling or warmth in the hands or arms - Hoarse voice Other very rare but more severe side effects include: - Bleeding due to vascular puncturing - Infection - Injury to the thyroid - Nerve damage