One autoimmune disease is far more prevalent in women than in men. In South Korea alone, approximately 1,000 women are newly diagnosed each year with systemic lupus erythematosus (hereafter, lupus).
Lupus is an autoimmune disease in which the immune system—designed to defend against foreign pathogens—malfunctions and attacks the body’s own healthy tissues, causing chronic inflammation. It frequently develops in young adults in their 20s to 40s who are actively engaged in school or the workforce.
Why does it disproportionately affect women? Do female sex hormones play a role?
While the exact etiology of lupus remains unknown, a complex interplay of genetic, environmental, hormonal, and immunological factors is believed to trigger the condition.
Above all, lupus carries a high incidence among women of childbearing age, who account for nearly 90% of all diagnosed cases. This stark disparity has led researchers to hypothesize that female hormones influence the onset of the disease.
Bae Sang-chul, an endowed chair professor at Hanyang University Hospital and a leading international authority on the disease, said in a phone interview with Comedydotcom on the 25th: “Estrogen, a female sex hormone, tends to provoke the abnormal immune response seen in lupus. Similar immune dysfunction can also occur when sex chromosomes are excessively activated.”
In general, females carry XX chromosomes. To prevent the overexpression of genes within cells, one of the two X chromosomes is typically inactivated. However, if both sets of genes remain active for any reason, it can contribute to the development of lupus.
“Women generally exhibit a more sensitive immune response than men when defending against foreign invaders,” Bae added. “Under normal conditions, this heightened resistance is beneficial, but when the immune response becomes overly aggressive, it can turn inward and develop into an autoimmune disease.”
Often Mistaken for a Cold or Joint Pain
Lupus is notoriously difficult to diagnose in its early stages. Initial symptoms—such as unexplained fatigue, joint pain, muscle aches, and low-grade fever—are easily mistaken for a severe cold or flu. Patients may also experience unexplained weight loss, hair loss, and anemia.
A hallmark cutaneous sign is the “butterfly rash,” characterized by red patches spreading across both cheeks and the bridge of the nose. While its presence strongly points to lupus, it does not manifest in this textbook form in every patient. Some patients display alternative symptom patterns, such as skin lesions that flare up primarily after sun exposure.
In addition, some patients experience recurrent oral mucosal ulcers or Raynaud’s phenomenon—episodes in which peripheral blood vessels constrict in cold conditions, causing the fingers and toes to turn pale or bluish.
Bae noted, “Because lupus is difficult to self-diagnose, many cases are discovered incidentally during routine health screenings. If a urinalysis reveals proteinuria, or blood tests confirm abnormal white blood cell or platelet counts or autoantibodies, we suspect lupus and conduct further diagnostic testing.”
If unexplained generalized pain, joint aching, or hair loss persists for more than a month, it should be recognized as a warning sign of immune system dysregulation. In such cases, patients should seek prompt medical evaluation for an accurate diagnosis.
Risk Escalates if Inflammation Spreads to Major Organs
When lupus manifestations are confined to the skin, the immediate clinical risk is relatively low. The critical danger arises when systemic inflammation spreads to major internal organs such as the kidneys, lungs, heart, and brain, significantly increasing the risk of severe complications.
If the condition progresses to lupus nephritis—an inflammatory involvement of the kidneys—it can cause proteinuria or hematuria, and in severe cases, lead to impaired renal function. When inflammation affects the lungs and pleura, it can cause chest pain and dyspnea (shortness of breath), or manifest as myocarditis in the heart. If inflammation affects the central nervous system, patients may experience neurological symptoms, including seizures or cognitive decline.
For these reasons, lupus treatment focuses primarily on controlling systemic inflammation, inducing remission, and preventing irreversible organ damage rather than aiming for a complete cure.
Nevertheless, if patients receive an early diagnosis before severe organ damage occurs, returning to a healthy, active lifestyle is entirely achievable. Lee Young-ho, a professor of rheumatology at Korea University Anam Hospital, emphasized that long-term disease management relies on consistent lifestyle habits and routine medical follow-ups after diagnosis.
“When lupus is diagnosed early and treated appropriately, patients can maintain a normal quality of life,” Lee said. “Alongside prescribed pharmacotherapy, maintaining healthy daily habits—such as regular exercise, a balanced diet, and sufficient rest—plays a vital role in preserving long-term health.”
