Warmer temperatures, blooming trees and sunshine mark the beginning of spring around the country. They also mark the beginning of "spring fever" season for individuals everywhere. But is this mysterious malady a real ailment or just a figment of the imagination?

University of North Carolina (UNC) psychologist Dr. Jon Abramowitz says spring fever isn’t a medical condition, but it can be explained.

That excitement many feel about getting to get outside after being cooped up for the winter may trigger the brain to secrete endorphins, pain-relieving chemicals that suffuse a person with feelings of well-being. Endorphins chemically resemble morphine, the narcotic derived from poppies.

"It may be that spring fever is actually a resolution of the blues we get during the winter," added UNC’s Dr. Thomas Koonce.

He added that variations in day length are associated with changes in levels of melatonin, a neurotransmitter involved in the regulation of sleep. Melatonin also plays a role in depression, which has been shown to peak during the winter months.

And, while the spring may help people to feel better and spend more time outdoors, healthcare experts suggest taking precautions to stay healthy outside. They include staying hydrated, beginning a new exercise program slowly and wearing sunscreen to protect the skin.