What are the most common causes to not feel any desire (sexual). is it psychologic?

Is this primary (never had it) or secondary (had it but lost it)? While there are occasional physical and hormonal causes, particularly toward and past menopause, libido is complicated and "psychological" oversimplifies it. There is individual variation as well as social and cultural factors and issues with gender identity and sexual orientation. Consult a sex therapist if one is available.

Please have a physical exam to know if you have an illness. If you are OK then your May benefit from seeing a Clinical Psychologist with expertise in multiple types of psychotherapy to help you overcome this problem and also help you determine if you need medication from a Psychiatrist.