Ischemia
The word "ischemia" () is from Greek ἴσχαιμος "iskhaimos", "staunching blood" from ἴσχω "iskhο", "keep back, restrain" and αἷμα "haima", "blood".
Syndemic
A syndemic is a synergistic epidemic. The term was developed by Merrill Singer in the mid-1990s, culminating in a 2009 textbook. Disease concentration, disease interaction, and their underlying social forces are the core concepts.
Disease co-occurrence, with or without interactions, is known as comorbidity and coinfection. The difference between "comorbid" and "syndemic" is per Mustanski et al. (2008:40) "comorbidity research tends to focus on the nosological issues of boundaries and overlap of diagnoses, while syndemic research focuses on communities experiencing co-occurring epidemics that additively increase negative health consequences." It is possible for two afflictions to be comorbid, but not syndemic i.e., the disorders are not epidemic in the studied population, or their co-occurrence is not accompanied by worsened health. Two or more diseases can be comorbid without interactions, or interaction occurs but it is beneficial, not deleterious. "Syndemic theory" seeks to draw attention to and provide a framework for the analysis of adverse disease interactions, including their causes and consequences for human life and well-being.