Thursday is National Hug Day Getty

From stress relief to reducing your risk of heart disease, there are plenty of reasons to give someone a hug. Thursday is National Hug Day, celebrated annually on 21 January – and here are five reasons why embracing someone is good for your health.

Feel-good factor

Embracing someone releases oxytocin, a powerful hormone which acts as a neurotransmitter in the brain. The hormone plays a significant role in social bonding. When oxytocin levels are driven up, stress chemicals like cortisol drop. "Oxytocin is a neuropeptide, which basically promotes feelings of devotion, trust and bonding," psychologist Matt Hertenstein, of DePauw University, told NPR.

Stress relief

A 2012 study found regular hugs can lower the risk of heart disease, combat stress and help curb fatigue, while boosting the immune system, fighting infections and easing depression. "The positive emotional experience of hugging gives rise to biochemical and physiological reactions," said psychologist Jan Astrom, who led the study report published in the journal Comprehensive Psychology.

Alleviate fear

Embracing others can help to alleviate fear and touch has the ability to help those who suffer from low self-esteem. "Even fleeting and seemingly trivial instances of interpersonal touch may help people to deal more effectively with existential concern. Interpersonal touch is such a powerful mechanism that even objects that simulate touch by another person may help to instill in people a sense of existential significance," according to Sander Koole, who published a study in the Association for Psychological Science.

Good for the heart

A study from the School of Medicine at the University of North Carolina-Chapel Hill found that the "heart rate increased 10 beats a minute for those without contact compared with five beats a minute for huggers."

Child development

Historical studies have shown hugs are a vital part of infant development. Neurobiologist Mary Carlson studied the long-term effects of babies who lacked physical contact and attention in Romanian orphanages in the 1970s and 1980s. She stated the starvation of touch negatively affected their behaviour into adulthood.