According to UCLA researchers, what makes you happy can actually impact your physical health.
Those closest to mother-of-four Hilda Hernandez say she always seems upbeat.
"She always has a smile on her face and is happy," said Citali Rivas, Hilda's daughter.
Researchers at the UCLA Cousins Center for psychoneuroimmunology say your state of mind affects your immune system and your genes. But living a stress-free, pleasurable life isn't enough.
"Well being as a whole doesn't promote these changes in the genetic profiles," said Dr. Michael Irwin of UCLA Cousins Center.
Researchers examined two different types of happiness, hedonic versus eudemonic.
Hedonic is a type of happiness that comes from consummatory self gratification. Eudemonic is more of the happiness that comes from having a meaning in life, a deep sense of purpose.
"There's something unique about this greater purpose of one's life that's altering the genes," said Dr. Irwin.
According to Dr. Irwin, people who consider themselves happy all reported a feeling well being and no depression.
But those who specifically think of themselves as having a sense of purpose had genetic markers that show a stronger immune system and less inflammation, two signs of health.
"They're less likely as a group to show cardiovascular disease as a subsequent health event or diabetes and certain kinds of cancers," said Dr. Irwin.
So do you have to emulate Mother Theresa to get these benefits? Dr. Irwin says many things like taking care of others give people purpose. He also says try mindfulness practices like meditation.
"Possibly through these kinds of practices and day to day integration in one's life, you can have a greater sense of purpose because you can see yourself connected to others and those around you," said Dr. Irwin.
Hilda says self reflection feeds her soul. She says she likes take walks.