Mild side effects can occur such as light-headedness, dizziness and nausea which are transient. A small bruise can occasionally occur from the session which will disappear after a few days. Unusually, certain health conditions may flare for a short time afterwards which settle to an improved state which indicates an effective treatment. Acupuncture is very safe when performed by a trained acupuncturist. Any side effects should be reported to your therapist.