Objective Night shift work has been linked to several chronic diseases such as gastrointestinal disorders, cardiovascular disease and diabetes, although the epidemiological data for rotating night shift nurses are inconclusive. The aim of our study was to assess the prevalence of selected diseases and symptoms among nurses and midwives according to their current system of work and the history of night shift work.

Methods We performed a cross-sectional study of 725 nurses and midwives (354 working on rotating night shifts and 371 daytime workers). Data were collected via an in-person interview, according to the “Standard Shiftwork Index”. The prevalence of particular diseases and symptoms were compared between the groups. The odds ratios were calculated with the logistic regression analysis adjusted for important confounding factors and they were calculated according to the frequency of night shifts in the current work schedule and the total duration of night shift work.

Results Chronic back pain, hypertension and thyroid disease were the most common diseases in the total population of nurses and midwives. The prevalence of thyroid disease was higher than in the general population of Polish women (21.2% vs. 10%) and the relative risk of this disease increased with increasing duration of night shifts work. The analysis did not show significantly higher frequency of any disease or symptom in the night shifts nurses compared to the day workers. The analysis showed significantly increased risk of feet swelling in women working 8 or more night shifts per month (OR = 8.55; 95% CI: 1.02–71.80).

Conclusions We did not find significant increased risk of any of the diseases or symptoms among night shifts nurses than among the women working only during the day. The increased prevalence of thyroid disease among the women with long duration of night shift work warrants further epidemiological studies.