Spring fever is a term applied to several sets of physical and psychological symptoms associated with the arrival of spring. In general it refers to an increase in energy, vitality and particularly sexual appetite, often particularly strong in those suffering from Seasonal affective disorder

Seasonal affective disorder

Seasonal affective disorder , also known as winter depression, winter blues, summer depression, summer blues, or seasonal depression, is a mood disorder in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or summer, spring or autumn...

 (SAD) and thus experiencing lows during the winter months. It is this sense that inspires the use of the term as a title for several works

Spring Fever

Spring Fever may refer to:* Spring fever, a syndrome of symptoms occurring during the spring season* Spring Fever , a silent, comedic short subject starring Harold Lloyd...

 of literature and entertainment. In some uses however it refers to the opposite, an unexpected loss of energy with the onset of spring.

Frühjahrsmüdigkeit

As a translation of the German term "Frühjahrsmüdigkeit" (lit. "Spring tiredness"), Spring Fever is the name for a temporary mood typically characterized by a state of low energy and weariness experienced by many people in springtime. It is not in the category of a diagnosed illness, but rather a phenomenon thought to be initiated by a change in the season.

Symptoms

In the northern hemisphere the symptoms usually arise from mid-March to mid-April, and depending on the person may be more or less pronounced. Weariness (despite an adequate amount of sleep), sensitivity to changes in the weather, dizziness, irritability, headaches, and sometimes aching joints and a lack of drive are the most common.

Causes

Although the causes of spring fever have not yet been fully resolved, hormone balance may play a role. According to this theory the body’s reserves of the “happiness hormone” serotonin

Serotonin

Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

, whose production depends on daylight, become exhausted over the winter, making it especially easy for the “sleep hormone” melatonin

Melatonin

Melatonin , also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes...

 to have its effect. When the days become longer in springtime, the body readjusts its hormone levels, and more endorphin

Endorphin

Endorphins are endogenous opioid peptides that function as neurotransmitters. They are produced by the pituitary gland and the hypothalamus in vertebrates during exercise, excitement, pain, consumption of spicy food, love and orgasm, and they resemble the opiates in their abilities to produce...

, testosterone

Testosterone

Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...

 and estrogen

Estrogen

Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...

are released. This changeover puts a heavy strain on the body, which responds with a feeling of tiredness.

In addition, temperatures usually fluctuate greatly in springtime. When temperatures rise, blood pressure drops, since the blood vessels expand. Food also plays a role. In winter one tends to consume more calories, fat and carbohydrates than in summer. But during the hormone adjustment period the body requires more vitamins and proteins instead.