The World Health Organization (WHO) has helped with this clinical challenge by issuing a list of conditions for which they have deemed evidence of efficacy to be strong or available but for which additional study is recommended, including Symptoms of cancer therapy Depression Dysmenorrhea Pain Headache Hypertension Post-operative symptoms Some complications of pregnancy Stroke complications Possible Adverse Effects and Contraindications Adverse effects of acupuncture are difficult to quantify and, although treatments are generally safe, skill and care vary among practitioners.