Lipoedema is a long-term condition that most commonly affects people assigned female at birth. It causes an uneven increase in fatty tissue (adipose tissue), often affecting the hips and legs and sometimes the arms. 

Lipoedema develops around puberty or early adulthood and may become more noticeable or worsen during hormonal changes, such as pregnancy or menopause. The exact cause is not fully understood, and research is ongoing to improve the diagnosis and treatment of the condition.