In The Wizard of Oz, green skin is symbolically associated with wickedness. Now, would you believe if I tell you there were real women, whose skin turned greenish-yellow and they weren't witches, but suffered from a rather rare medical condition. Chlorosis, commonly referred to as "green sickness," is an old medical term that described a condition in which a person's skin appeared greenish-yellow, particularly in young women. While chlorosis was most commonly observed in the 18th and 19th centuries, it is now understood as a form of hypochromic anemia—a condition in which red blood cells appear paler than normal due to insufficient hemoglobin.What Happens When You Don't Have Enough Hemoglobin?Hemoglobin is the iron-rich protein in red blood cells responsible for carrying oxygen throughout the body. When there is not enough hemoglobin, the body's tissues don’t get the oxygen they need. As a result, symptoms such as fatigue, pallor, and weakness appear. This also manifests in conditions such as chlorosis—distinctive greenish tint to the skin. In the past, this condition was often linked to poor nutrition, particularly iron deficiency, or to emotional stress. Research from the National Library of Medicine shows that chlorosis was frequently observed in young women, particularly those who were inactive or had poor dietary habits. At the time, it was often seen as a disease of young, undernourished girls.While the classic appearance of green skin has been less commonly observed in contemporary times, the underlying condition of hypochromic anemia remains relevant. Anemia, and more specifically iron-deficiency anemia, is still one of the most common nutritional deficiencies worldwide, particularly among women of reproductive age. According to a study published in The Lancet Haematology, approximately 30% of the global population is affected by iron deficiency anemia, with women and children being the most vulnerable groups.Chlorosis was often linked to the physical symptoms of exhaustion, shortness of breath, halted menstruation, loss of appetite, and a bluish tint in the sclera (the whites of the eyes). The symptoms are common to modern day Anemia, which include:Dizziness or feeling like you are about to pass outFast or unusual heartbeatHeadachePain, including in your bones, chest, belly, and jointsProblems with growth, for children and teensShortness of breathSkin that’s pale or yellowCold hands and feetTiredness or weaknessChlorosis Was Linked To Hysterical PersonalitiesIn the 18th and 19th centuries, the diagnosis of chlorosis was often confused with other conditions. The belief that it was caused by emotional distress or excessive modesty was widespread, with some physicians suggesting that the condition was linked to young women’s "hysterical" personalities. However, modern research, including studies published in The Journal of Clinical Investigation, has proven that chlorosis was primarily caused by physical health issues such as malnutrition and iron deficiency, rather than psychological or emotional stress alone.The condition's historical association with women’s health has also led to the modern recognition of gendered patterns in anemia. A 2015 study published in The American Journal of Clinical Nutrition found that women, especially those who are pregnant or menstruating, are at a higher risk for developing iron deficiency anemia. This is due to the increased iron demands of menstruation, pregnancy, and breastfeeding.Chlorosis, while a condition of the past, helped shape the modern understanding of anemia and its treatment. Today, iron deficiency is treatable with supplements, improved dietary habits, and addressing underlying causes, but it remains an important global health concern.