Liking the people you鈥檙e around may not just be good for your mental health 鈥 it could also be good for your physical and physiological health too.

According to a new study published last week in the journal Social Psychological and Personality Science, the way you feel about your close personal relationships on a day-to-day basis may

"Both positive and negative experiences in our relationships contribute to our daily stress, coping, and physiology, like blood pressure and heart rate reactivity," Brian Don, lead author of the study with the University of Auckland, New Zealand, "Additionally, it's not just how we feel about our relationships overall that matters; the ups and downs are important too.鈥

While previous research has looked at the impact that conflict within relationships has upon the body in terms of blood pressure or stress levels, this new research cast a wider net by looking at whether positive relationships had an impact on physical health as well as negative ones.

Researchers tracked more than 4,000 participants drawn from all over the world over the course of three weeks. During that time, participants were required to check in daily through an app on their smartphone or smartwatch, giving information about their blood pressure, heart rate, stress and how they were coping on a day-to-day basis. Every third day, they would complete reflections on their current feelings about their closest relationship, focusing on both positive and negative experiences and feelings concerning that person.

In general, people who reported more positive experiences with their closest relationship were more likely to also have lower blood pressure and lower reported stress levels, along with better coping.

Researchers also observed that overall negative relationships that saw a lot of daily ping-ponging between improving and getting worse were predictive of more stress, poorer coping and higher blood pressure.

Those who had the highest overall positive relationships were less likely to report a wide margin of variability in their day-to-day experiences with that person, while those with the most overall negative relationships reported greater negative variability, suggesting an erratic relationship with someone could be a contributor to its overall negativity.

The blood pressure and heart rate measurements were recorded using an optic sensor that comes with some Samsung phones and smartwatches, such as the Galaxy S9.

Researchers said that this data raises the question of how outside factors impact relationships, and thus physiological health. For instance, this could be yet another way that the COVID-19 pandemic has impacted the health of the global population, they suggest.

"Since the COVID-19 pandemic, relationships have been facing unprecedented challenges, turbulence, and change," Don said. "What this means is that the COVID pandemic may have health implications not just because of the virus itself, but also indirectly as a result of the impact it has on people's relationships. That is, because the COVID-19 pandemic has created considerable strain, turbulence, and variability in people's relationships, it may indirectly alter stress, coping, and physiology in daily life, all of which have important implications for physical well-being.鈥

Researchers stated that while the overall impact of negative relational experiences on blood pressure in particular was small, the pattern they observed could become a larger problem if it contributed to elevated blood pressure throughout everyday life, potentially accumulating into 鈥渓ong-term physiological harm.鈥

The study didn鈥檛 stratify participant responses based on what type of close relationship they were reporting their experiences about, meaning they didn鈥檛 measure whether a negative romantic relationship, for example, might be more detrimental to health than a negative close friend relationship.

The study also was limited by their sample, as participants were around 48 years old on average, with around 65 per cent male participants and 35 per cent female participants. Three quarters of participants were white, and the majority hailed from the U.S.

It鈥檚 important to note also that this study only looked at the association between these factors, and doesn鈥檛 contain evidence of a causal link between feeling down about a close relationship and experiencing physical impacts.

Researchers are hoping that further examination will be able to establish the biological processes behind why a person鈥檚 overall blood pressure or stress levels may increase after a fight with a close friend.

"It would be useful to examine other physiological states, such as neuroendocrine or sympathetic nervous system responses as outcomes of daily positive and negative relationship experiences, which may reveal different patterns of associations,鈥 Don said.