It is probably a result of the brain releasing "feel-good" hormones such as endorphins in response to treatment.

You might know endorphins as the "feel-good" hormones of the body.

"There's definitely a connection between carbs and the release of serotonin, your body's feel-good hormone, in the brain," says Aronica.

It also improves morale and reduces pain by releasing endorphins, the feel-good hormones in the brain.

It's been shown to reduce stress and release feel-good hormones.

When you pet your dog even for just a few minutes, your body releases feel-good hormones like serotonin, prolactin, and oxytocin.

"It reduces stress hormones and cholesterol, releases feel-good hormones, and amps up the immune system."

Massage may also trigger the release of feel-good hormones like dopamine and serotonin.

"It's a combination of caffeine, sugar and chemicals that affect your serotonin levels a feel-good hormone."

For example, key nutrients you get in certain foods can influence the levels of feel-good hormones such as serotonin.