Both physical and psychological factors can contribute to female orgasmic disorder:

Medical conditions. Diabetes, vascular disease, multiple sclerosis, spinal cord injury and certain pelvic conditions may interfere with a woman’s ability to reach orgasm. FOD has also been associated with arthritis, thyroid problems, and asthma.
Medications. Antidepressants [particularly serotonin reuptake inhibitors (SSRIs)], antipsychotics, and drugs taken for cancer, high blood pressure, and heart disease can have sexual side effects that affect orgasm.
Sexual inexperience. Some women have not yet learned what types of stimulation bring them to orgasm. Or, they might not know how to talk to their partner about what gives them pleasure.
Guilty feelings about sex. Women may have been brought up to believe that they shouldn’t enjoy sex, so they feel guilty or “wrong” for doing so.
Anxiety and depression. A woman may feel so anxious about sex that she is unable to relax enough to have an orgasm. Or, she may focus so much on negative events that she is unable to be “in the moment” and enjoy stimulation. For some women, poor body image causes anxiety. Others fear losing self-control during orgasm.
Relationship issues. Conflict with her partner can make a woman less likely to reach orgasm. This could be due to sexual problems in the relationship, general relationship problems, anger, mistrust, or inability to communicate.
Past abuse. Women who have been physically, psychologically, or sexually abused often have trouble with orgasm.