Surgery causes stress through pain, discomfort, worries about survival and recovery, separation from family and friends, and lack of familiarity with the personnel and the hospital surroundings. Research in a Korean hospital (2009) determined whether exposure to plants had positive effects on health outcomes of 90 surgical patients using various medical and psychological measurements. Half the patients had plants placed in their rooms during recovery, and data was collected from the length of hospitalization, analgesics used for pain control, vital signs, ratings of pain intensity, pain distress, anxiety and fatigue, and satisfaction to the room.

Patients in rooms with plants had lower hospitalization time and used less analgesics, but the differences were not significant likely due to small hospitalization times. However, it was found that patients in room with plants had significantly more positive physiologic responses by

• Lower blood pressure
• Lower ratings of pain intensity and distress, anxiety, and fatigue
• Feeling more positive, calming, happy and satisfied about their rooms

The study also found, that 93% of patients in rooms with plants would like to return to the room in any future hospitalization, as the same figure for the patients in lean rooms was only 73%. Patients rated the most positive qualities of their rooms, and for the plant rooms it was the plants (96%), others being sunshine (80%), temperature (67%), and television (44%). For the lean room the best quality was temperature (88%), followed by television (86%), sunshine (71%), and quietness (22%).

Viewing plants had a positive influence directly to the health outcomes of the patients. Plants were concluded to have therapeutic values and should be used as non-invasive, inexpensive, and effective method for better recovery.