Men and Women have low self esteem but to answer your question, women have low self esteem because:
1. They are neglected. Women who feel neglected by their family and friends will feel that they are not good enough. When you don't feel good enough, you will feel your existence is worthless.
2. Negative Peers. Women who are surrounded by negative peers face peer pressure. If you are surrounded by bad peers, you will compromise yourself and then feel ashamed later for going against your personal morals
3. Trauma. Abuse whether physical, emotional, sexual or a combination of these often causes feelings of shame and even guilt. She may feel that she did something to deserve the abuse.
4. Body Image. From the moment we’re born, we’re surrounded by unrealistic images of what women should look like, what the “ideal” body type is. Women’s bodies are constantly objectified in the media, making it seem as though their bodies exist for others to look at, touch, use, etc.
5. Previous Bad Choices. Not being able to get over your past mistakes can wear you down.