What can be the main cause of pressure, spasms, and pain in the lower left side of abdomen in a female?

Variable: Anatomical , colon, ovary, tube, small bowel, kidney ureter stones, venous obstruction. Causes infection, perforation, stones, polyps, cysts, cancers.

Many things : There is a multitude of things that can cause this discomfort: inguinal hernia, femoral hernia, ovarian cyst, endometriosis, ovarian torsion, kidney stone, UTI. See your primary doctor for help.