According to the Mayo Clinic, an inflamed uterus could be a result of pelvic inflammatory disease. Fibroids in the uterus can also cause swelling and discomfort.
Pelvic inflammatory disease is a fallopian tube infection that also affects the uterus, ovaries and cervix. If the condition is not treated, scar tissue can develop and cause damage to the female reproductive organs, says the Mayo Clinic. Uterine fibroids, according to the Mayo Clinic, are benign growths that develop on the uterus, usually during a woman's childbearing years. Symptoms can include long menstrual cycles, heavy menstrual bleeding, back and leg pain and pelvic pressure.