PRL and Headache: Studies have shown that there is an association between increased prolactin levels and blood pressure, cardiovascular disease, diabetes type 2 (Corona et al., 2011), rheumatoid arthritis (Fojtíková et al., 2010), inflammatory diseases, pain (Patil et al., 2013), and neurological diseases such as headache (Pineyro et al., 2017) and multiple sclerosis (Wei et al., 2017).