This study investigated the complex biochemical responses to personally meaningful everyday stressors in a patient with systemic lupus erythematosus (SLE). For this purpose, a 52 year-old woman with SLE collected her entire urine for 56 days on a 12-h basis for the determination of cortisol as well as neopterin, a cellular immune parameter. Additionally, using questionnaires, daily notes and interviews, extensive psychosocial and psychological time-series data were collected every 12 h. Cross-correlational analyses of the resulting time-series revealed that stressful incidents were associated with cyclic fluctuations in both urine cortisol and urine neopterin. Specifically, whenever the patient anticipated a moderately stressful incident, urine cortisol initially increased 24 h before the incident and then decreased 12 h before the incident. Moderate stressors not anticipated by the patient were associated with an initial increase 24 h following the incident and then with a decrease after a total of 36 h. Moreover, stressors having to do with the patient's extramarital relationship were followed initially by a decrease in urine neopterin after 36 h and then by an increase after a total of 60 h. Our findings indicate that when investigating the relationship between psychosocial stressors and biochemical activity in SLE, appropriate consideration of the data's dynamic nature may be necessary to avoid flawed conclusions.