Whether it is a close friendship or an intimate relationship, social interaction is needed to prevent health decline in seniors. Loneliness is a risk factor for functional decline in adults over the age of 60. Something as simple as a friendship can enhance aging hearts and strengthen the immune system. Companionship can decrease the physical risk of disease by lowering blood pressure, heart rate, and cholesterol. The psychological benefits include increased self-esteem, decreased stress, and a sense of belonging. Older adults can also benefit from having a pet. Dogs, in particular, can open seniors up to new activities and interests.