Research settles age-old debate of whether men or women can tolerate pain better

What's worse - a kick to the groin or childbirth? 

Men and women have long argued about which sex can handle pain better, but research appears to have answered that question.

Studies over recent decades show that women suffer pain at noticeably higher rates than men, with many suggesting it has to do with different hormone levels.

Testosterone, which is higher in men, inhibits pain by determining how the body recognizes and transmits aches, discomfort and other chronic pain.

Yet the answer could be more than just biology, according to researchers, who have found that stress, childhood trauma, depression and anxiety have also been shown to exacerbate pain. 

'The biological processing of pain, regardless of how much pain is produced, is dramatically sex dependent,' Jeffrey Mogil, a psychology professor at McGill University, told The Hill. 

'Different genes are being used in both sexes, different proteins, different cell types, dramatically different biology in each case.'

Women often state that enduring childbirth makes them more tolerant to pain than men, however, the opposite is actually the case.

Hormones play a crucial role while giving birth, with more endorphins, adrenaline and oxytocin being released that are believed to make women less sensitive to pain before returning to normal after birth.

According to a June study, prolactin - the hormone in women that produces breast milk - increases the sensory receptors in the body that processes pain. 

Researchers at the University of Arizona identified functional sex differences in the nerve cells that produce pain, called nociceptors.

Nociceptors are activated when a person is injured, triggering a reaction that causes humans to remove themselves from the source of danger - like placing your hand on a stovetop or experiencing the jarring sting from a jellyfish.

The study did 'not show that pain is worse in men or women, but rather that the nociceptors in men and women are different,' Dr Frank Porreca, the research director of the Comprehensive Center for Pain & Addiction and and the study's lead author, previously told DailyMail.com.

However, more than the nerve receptors and hormonal levels are at play, research has shown that pain is 'multifactorial,' Diane Hoffmann, the director of the University of Maryland Law School's law and health care program told The Hill.

Stress, depression and anxiety have all been linked to worsen pain while trauma developed in childhood can increase a person's chance of developing chronic pain as they get older, a 2001 study revealed.

All four problems were found to be higher in women than men, further revealing that women's pain tolerance threshold is lower than their male counterparts. 

'You can't just look at the biological and physiological,' Hoffmann told the outlet. 'You have to look at that in combination with not just the psychological, but social and cultural impacts and how they affect a person's experience of pain as well.'

The studies could help researchers develop medication specifically geared toward treating women and men separately.

'This provides an opportunity to treat pain specifically and potentially better in men or women, and that's what we're trying to do,' Dr Porreca said.

The US Food and Drug Administration's existing approval of orexin receptor antagonists which treat sleep disorders would make it easier to prevent nociceptor sensitization.

'We are bringing the concept of precision medicine – taking a patient's genetics into account to design a therapy – to the treatment of pain,' Dr Porreca added. 

'The most basic genetic difference is, is the patient male or female? Maybe that should be the first consideration when it comes to treating pain.'