During a difficult event, women secrete high levels of oxytocin, the "feel-good" chemical in the brain that encourages relaxation. "Oxytocin counteracts cortisol in stressful situations," says Rivers. "It signals the need for social support." Men release the same hormone in much smaller amounts, which may explain why the sexes respond to stress so differently.
Read more of why in today's 24/7, go-go-go world, stress is unavoidable--but not necessarily a bad thing.