Being in a romantic relationship confers better psychological wellbeing and physical health than being single; however, relationship dissolution can be psychologically stressful, and separation and divorce have been linked to an array of poor health outcomes. Nonetheless, there has been no known research to date regarding the health effects of nonmarital breakups. Additionally, recent research has implicated distress as a possible cause for the health effects of relationship dissolution. Individual factors, such as the tendency to regulate emotions using rumination or avoidance, may also magnify the negative effects of breakups on health via increased distress. The current research project examined 1) whether nonmarital breakups compromise physiological functioning, 2) whether physiological dysregulation is associated with breakup distress, and 3) whether these effects are driven by the tendency to use ruminative or avoidant emotion regulation strategies. No significant differences were found between participants who experienced a recent breakup and those who were continuously in a relationship on stress-related health outcomes, nor was breakup distress associated with any physical health marker. Emotional avoidance was directly and positively associated with diastolic blood pressure in those who experienced a recent breakup (p < .05), suggesting that the tendency to avoid negative emotions following a stressor can place strain on the cardiovascular system. Rumination was directly and inversely associated with inflammation in participants with a recent breakup (p < .05). Results suggest that although nonmarital breakups alone may not be related to poorer health, ways of regulating emotions following a breakup may impact health. More research is needed to fully understand how healthy emerging adults physically respond to the stress of a breakup.