First, it’s important to understand uterine fibroids. Uterine fibroids affect about 40% to 80% of women. Risk factors like a higher body weight, not having children and a family history of fibroids can increase your chances of getting uterine fibroids. Uterine fibroids are benign tumors or growths from the muscle wall of the uterus. They can grow inside the uterus or they can grow on the outer surface of the uterus. Hormones like estrogen and progesterone, which are prevalent during childbearing years and start to decrease during menopause, can increase your risk of uterine fibroids. You may have one uterine fibroid or you may have many that grow in a cluster. The size of a single fibroid can vary greatly. It can be really small — a couple of millimeters, which is the size of a pea or marble — or a larger fibroid could be the size of an orange or grapefruit. Or in rare situations, a uterine fibroid can be greater than 10 centimeters, which is the size of a melon. And as uterine fibroids grow, they can cause abdominal bulge or bloating. That can certainly give an appearance of weight gain or increased abdominal girth. If someone has larger fibroids, it can create a visible abdominal bulge. Uterine fibroids don’t typically cause weight gain. Smaller fibroids typically don’t weigh much, maybe a few grams. But in rare cases, large fibroids could weigh about four or five pounds. An important distinction: The mass and size of a uterine fibroid can cause weight gain, meaning it’s unlikely that a uterine fibroid is causing other metabolic or systemic changes that lead to true weight gain