  Social media data has been increasingly used to study biomedical and
health-related phenomena. From cohort level discussions of a condition to
planetary level analyses of sentiment, social media has provided scientists
with unprecedented amounts of data to study human behavior and response
associated with a variety of health conditions and medical treatments. Here we
review recent work in mining social media for biomedical, epidemiological, and
social phenomena information relevant to the multilevel complexity of human
health. We pay particular attention to topics where social media data analysis
has shown the most progress, including pharmacovigilance, sentiment analysis
especially for mental health, and other areas. We also discuss a variety of
innovative uses of social media data for health-related applications and
important limitations in social media data access and use.
