Why are autoimmune diseases more common in females than in males?

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immune system disorder False-color scanning electron micrograph of a T cell infected with HIV (human immunodeficiency virus), the agent that causes AIDS (acquired immunodeficiency syndrome).

It is a well-documented observation that most autoimmune diseases affect females significantly more often than males. While this trend is clear across many well-known conditions—such as rheumatoid arthritis, systemic lupus erythematosus, myasthenia gravis, Graves disease, and Hashimoto disease—the precise underlying cause remains a subject of ongoing scientific research.12

Researchers currently believe that the disparity is likely related to the influence of hormones on immune system responses. While genetic factors and environmental triggers also play significant roles in the development of these disorders, the hormonal differences between sexes are considered a primary area of interest for explaining why women are disproportionately affected.12