By writing about traumatic, stressful or emotional events, participants were significantly more likely to have fewer illnesses and be less affected by trauma. Participants ultimately spent less time in the hospital, enjoyed lower blood pressure and had better liver functionality than their counterparts.
It turns out writing can make physical wounds heal faster as well. In 2013, New Zealand researchers monitored the recovery of wounds from medically necessary biopsies on 49 healthy adults. The adults wrote about their thoughts and feelings for just 20 minutes, three days in a row, two weeks before the biopsy. Eleven days later, 76% of the group that wrote had fully healed. Fifty-eight percent of the control group had not recovered. The study concluded that writing about distressing events helped participants make sense of the events and reduce distress.
Even those who suffer from specific diseases can improve their health through writing. Studies have shown that people with asthma who write have fewer attacks than those who don't; AIDS patients who write have higher T-cell counts. Cancer patients who write have more optimistic perspectives and improved quality of life.