Between the mid-16^th and early 20^th centuries, the green disease (also known as chlorosis, lover fever, or virgin disease) was a gendered condition that was placed on young teenage girls who had numerous symptoms and sometimes a greenish tinge or paleness to their skin.  

It was originally associated with virginity in 1554, when physician Johannes Lange first wrote about the disease. Although it was described before and after this date, he called it “the disease of virgins”; this may have moved it from a digestive disorder affecting anyone, as originally thought, to a condition only found in women. It then became known as chlorosis in the 17^th century, from the Greek chloros, which meant a yellow shade of green. Then finally in the 19^th century, it was known as hypochromic anemia.

The symptoms included fatigue, moodiness, or lack of appetite – which coincidentally are also side-effects of hormonal changes during the menstrual cycle. Other symptoms included heart palpitations, fainting spells, weakness, paleness, and the absence of menstruation.

The main cause was thought to be that the blood did not leave the body through menstruation but was retained, with any excess blood causing disruption elsewhere in the body. Sex or very vigorous activity was thought to help the blood circulate again.  

And, what did people think the cure was? Well, of course, marriage – followed swiftly by sex, pregnancy, and childbirth. People believed that sex would open up the body more and allow the retained blood to move around. So, this was a way to get young adults married and more into line with societal expectations. Although, there were also some ideas from physicians that physical activity like horseback riding could be a cure.

People did fear this disease as it was thought that the illness was a cause of death. In fact, John Graunt produced "A Table of Casualties" for the City of London, and showed that in 1659, 186 people died of this disease; although, it was called “Stopping of the Stomach”, because people did not write green sickness as it was shameful way to die. As they thought: “For since the World believes, that Marriage cures it, it may seem a shame, that any Maid should die uncured…”.

Usually, women were also slapped with condition if they were not behaving as society expected. This disease was in contrast to hysteria, in which the patient was difficult to control, but instead presented as more passive and submissive. 

Green sickness was also a condition that was assigned to people who may have been less extroverted, those that were classed as fragile or weak, or even "feeble boys". Although the latter was rarer, male green sickness was mentioned by Shakespeare in Henry IV Part 2. Often, in reference to men, this was used as an insult.

But, in the modern day, what is this disease?

Well, if the person had physiological symptoms and not just unwanted behaviors, then it could have been associated with many different conditions. For instance, the green hue to the skin could have been linked to anemia, which is when the body does not have enough iron. If someone has low melanin mixed with the reduced hemoglobin in anemic blood, this could produce a green hue.

Other reasons for the symptoms could have been malnutrition, anorexia, or even pica.

So what happened to the sickness? During the late 19^th century, the rates of admissions with the disease to St Bartholomew's Hospital, London and St Georg Hospital, Hamburg were at 16 percent, and this then dwindled to zero by the 1920s. This was probably due to the increased iron intake in people's diet, iron supplements, and an increased knowledge about the human body.