“In the spring a young man’s fancy lightly turns to thoughts of love” … or chronobiology.
– apologies to Lord Alford Tennyson.
Spring Fever has at least two meanings; an increase in energy and a brightening of mood when “your thoughts turn to love” OR lassitude, fatigue, and even depression which slows you down and saps your energy. Neither actually raises your temperature, but it is called “fever” none the less, and there is no medical diagnostic code for it either. Since there are two diametrically opposed definitions of spring fever, it is not surprising that there are two different explanations of its cause.
Both theories relate it to the effect of increased daylight on our pineal body deep in the hypothalamus of our brain. The pineal body is sometimes called “the third eye” and is an element of the 6th Charka. In lower species the pineal structure is actually light-sensitive and is, in fact, a real third eye. In humans the pineal body is an endocrine gland associated with melanin production and a regulator of our circadian rhythm. (Boy, that is an eyeful of sentences for someone who is not a biology major. Sorry)
Multiple poets herald the positive side of spring fever as we emerge from the winter greyness and short days into the spring sunshine and blooming flowers. The negative viewpoint of spring fever, sometimes called “spring depression”, relate the feelings of lassitude to seasonal allergies, “reverse seasonal affect disorder” and point to the springtime peak in suicide rates as support for their view.
Both theories use what we do know about springtime hormonal shifts to explain their drastically different conclusions. Both consider the changes as caused by increased daylight. According to the “negative” theorists the reservoir of serotonin, the “happy hormone”, becomes “exhausted” in the long nights and short days of winter and melatonin, the “sleep hormone”, dominates. In the spring, increasing daylight increases the production of endorphins, testosterone, and estrogen and melatonin decreases. “The changeover puts a heavy strain on the body resulting in a feeling of tiredness”. According to the “positive” theorists those same changes in “sex hormones” cause the increased energy and interests of the poet’s spring fever. Much of what is written about spring fever in Wikipedia is done “without citation” which means it is opinion rather than fact. We actually don’t know enough to label one or the other theories as “alternative fact”.
All agree that spring fever does have something to do with the increased amount of daylight. So, the timing of spring fever varies with your distance from the equator. The further North you are the later the onset. According to one reporter in Germany up to 50-75% of people suffer from Fruhjarsmudigkeit , “Spring fatigue“, from mid-March to mid-April. Germany seems to be the center of study of this phenomenon described as “mild jet lag”, another state of temporary fatigue related to disturbance of circadian rhythms. Of course in Australia, spring fever occurs from the start of September to the end of November.
Fox News suggests that spring fever is the result of 3 factors: 1) increased daylight, 2) more exercise as we spend more time outdoors, and 3) the “reappearance of the female form” as winter clothes are shed.
“With days getting longer, weather getting warmer and women getting, well, ‘nakeder’,
it’s no surprise that spring impacts male mood and excitement. Whether the so-called spring fever
is a real biological phenomenon or not, it is clear that in the end,
it all essentially boils down to hormones.”
– published March 13, 2011, Fox News “We Report, You Decide”