Had spine mri. Showed 4 compression fractures. And bone marrow edema is diffusely of low signal intensity. What does this mean? I'm only 39

Needs evaluation. Unless you lift pianos for a living, then you should not be getting vertebral compression fractures at age 39. Have you had your ovaries removed? If so, and you've not had hormone replacement therapy then a lack of estrogen could cause increased osteoporosis. Diseases of the bone marrow can also cause weakened vertebrae, so I'd start by checking blood counts, and serum protein electrophoresis.