Forget stress balls or breathing exercises.

Aromatherapy might be the best way of dealing with the pressures of work, researchers think.

Nurses who wore a vial of rose oil around their neck for a month — allowing them to inhale the floral smell everywhere they went — saw their stress levels drop by more than a tenth.

Experts in Iran claim the approach 'effectively reduced job stress', and its effects could be even greater with continued use, reported MailOnline.

When anxious or scared, the body releases stress hormones such as adrenaline and cortisol. Most people feel stressed sometimes and some people find it helpful or even motivating. But for some, stress can cause symptoms that interfere with daily life.

These include physical symptoms, such as headaches, muscle tension and stomach problems and mental symptoms, including difficulty concentrating, constantly worrying and being forgetful.

Some also have changes in their behaviour, becoming irritable and eating or sleeping too much or too little. Stress can be triggered by work, family, financial issues or health problems.

The NHS advises people struggling with stress to talk to friends, family or a doctor, use breathing exercises and plan ahead for stressful events.

The centuries-old therapy, which was practised in Ancient Egypt, China and India, typically involves inhaling or massaging oils to boost mental health or ease pain.

But some studies have rubbished aromatherapy — warning it triggers no benefits. Stress, the body's reaction to feeling threatened or under pressure, is common and can be motivating.

But high levels over time can trigger mental exhaustion and anxiety, as well as high blood pressure, sleeping difficulties and changes in appetite.

Previous studies have shown nurses can experience extremely high levels of stress, to the point that it harms their job performance and personal life — leading to some leaving work. Alternative therapies — including yoga, acupuncture and meditation — have all been advocated to ease stress.

But a team at Semnan University of Medical Sciences claimed that aromatherapy is another option. To determine whether the therapy could lower nurses' stress, Mohsen Emadikhalaf and colleagues recruited 118 medics working at two hospitals in Iran.

The nurses, aged 36 and in the profession for over a decade, on average, were split into three groups. They were either given a 0.5ml tube of lavender or rose oil — both of which are said to lower stress and boost sleep quality — to clip onto their shirt, while the placebo group were given sesame oil.

The medics were given the vile at the start of their shift and wore it for two hours every day for four weeks. Each volunteer was quizzed on their health and completed a questionnaire on their stress levels on the first day of the trial, then at follow-ups two and four weeks later.

A score between 104-136, the maximum, signalled high levels of stress, while 69-103 suggested moderate stress. Below 68 was considered low.

The results, published in Explore: The Journal of Science & Healing, show that after two weeks, there was no significant impact on stress levels.

But after four weeks, those inhaling the rose scent saw their stress score plummet 13 per cent from 85 to 74, on average. For comparison, those in the sesame oil group saw their score just drop from 88 to 86 (two per cent).

This means nurses in the rose oil group scored 12 points lower on the stress test than the control group at the end of the study.

Nurses exposed to lavender saw their stress levels drop by a tenth from 89 to 80 — though the team said this was not as statistically significant — as these participants scored just six points lower on stress than the sesame cohort.

“Rose scent for two hours a day and during a long period of time effectively reduced job stress among the nurses,” the researchers wrote.

“Considering that job stress in both intervention groups decreased over time, the effect of aromatherapy can be cumulative and augmented over time with the continued use,” they added.

The team suggested the effect was down to how the oils influence the brain and nervous system.