Prolonged Duty Hours Found To Disturb Biological Stress Cycles In Nurses

The strain of long working hours in healthcare settings may be running deeper than visible fatigue, with new research suggesting that extended duty shifts could be altering the body’s stress response in nurses. At a time when India’s public health system continues to rely heavily on an overburdened nursing workforce, the findings raise fresh concerns about the long-term health of frontline caregivers.

A study published in the journal Nursing Open has found that nurses working double shifts experience significant disruption in their cortisol levels—a key hormone that regulates stress, sleep cycles, and the body’s internal clock. Cortisol typically follows a predictable daily rhythm, peaking in the morning to help the body prepare for the day and gradually declining by night. However, extended working hours appear to disturb this natural balance.

The research, led by Fadime Ulupınar, analyzed 52 female nurses, comparing those working single shifts with those on back-to-back or double shifts. Saliva samples were collected at multiple points during the day—before the shift, after the shift, and at midnight—to track hormonal changes.

The results revealed a clear disruption. While cortisol levels were highest in the early morning, as expected, nurses working double shifts showed consistently elevated levels throughout the day. Most notably, their cortisol levels spiked sharply at midnight—nearly double those recorded in nurses working regular shifts.

Researchers observed a strong association between longer working hours and altered cortisol patterns, indicating that extended shifts directly affect how the body manages stress. According to Ulupınar, such changes reflect a disturbance in the body’s circadian rhythm—the internal system that regulates sleep, hormone release, and overall physiological balance.

Though the study was conducted outside India, its implications are particularly relevant in the Indian context, where nurses often work prolonged hours due to staff shortages, high patient loads, and systemic constraints in both public and private healthcare facilities.

A senior nurse in a government hospital in Delhi agreed with the study observation, pointing out that in many government hospitals across India, nurses frequently work beyond standard shift timings, sometimes covering double duties in emergency situations or due to inadequate staffing.

The COVID-19 pandemic further exposed the extent of this burden, with nurses working extended hours under physically and emotionally demanding conditions.

Disruptions in cortisol levels are not merely a biological observation; they can have wider health implications. Persistently elevated stress hormones have been linked to sleep disturbances, fatigue, weakened immunity, metabolic disorders, and even mental health issues such as anxiety and burnout.

Yet another nurse, on the condition of anonymity, said that such physiological stress may gradually affect not only the well-being of nurses but also the quality of patient care. Fatigue and impaired concentration can increase the risk of errors, especially in high-pressure environments such as intensive care units and emergency wards.

The findings add to growing evidence that the healthcare system must address working conditions for its workforce more urgently. While nursing remains one of the most critical pillars of patient care, it is also among the most physically and emotionally demanding professions.

Public health specialists have long argued for structural reforms—including better staffing ratios, regulated shift durations, and institutional support systems—to reduce occupational stress among nurses. However, implementation remains uneven across states and institutions.

According to Mathew George, Professor of Public Health and Community Medicine at the Central University of Kerala, nurse shortages cannot be viewed in isolation.

"Nurse shortages only become visible when systems have adequate doctors, beds, and infrastructure. In many public facilities, infrastructure inadequacy hides workforce shortages. We also fail to clearly define the different categories of nurses and their roles," he is quoted as saying to a news website.

He highlighted the lack of structured professional pathways, such as nurse practitioners and midwifery-led care models, which are well-established in countries like the UK.

Yet another international study published in JAMA Network Open had found that hospitals with better nurse staffing and supportive work environments not only improve outcomes for nurses but also significantly reduce physician burnout and job dissatisfaction.