Sex is not only important for procreation, it is also very important for the general well-being of human beings and the brain is the most important sex organ in the body. It is also important to know that functional sex organs, appropriate hormone levels, and the ability to become sexually aroused alone do not guarantee good sex. Other factors such as the brain factor, emotional and psychological issues can get in the way of good sex.

Relationship issues: Tension and emotional distance can undermine a couple’s sex life. Other forms of conflicts; which have nothing to do with sex, like finances or child-raising issues, can be at the root of a sexual problem. It can be the other way round too, because, a sexual issue can strain a couple’s ability to get along and have a god sex life

Physical and body changes: The physical transformations the body undergoes with age have a major influence on sexuality. Chronic illnesses, common medications and emotional issues can influence sexual capabilities. If as individuals we cannot learn to accept and manage these physical changes, appreciating and enjoying good sex will be impossible because of the psychological problems these changes cold create.

Performance anxiety: A person may become worried about sexual performance, that sex is not enjoyable, or even possible. Performance anxiety becomes more common for both men and women as they move into their 50s.

Body image and self-esteem: There are plenty of things that can make a person feel less than sexy. Gravity is not kind to the body as it ages. Childbirth, a poor diet, weight gain, or thinning hair can also leave a person feeling less than desirable. Such feelings can get in the way of a sense of closeness or inspired lovemaking and can inhibit a person from initiating or responding to sexual advances.
Environment, expectations and past experiences: Your sexuality is a natural drive that is with you from birth, but your family, culture, religious background, the media, and your peers shape your attitudes towards sex. For some people, this history supports a healthy enjoyment of sex. For others, it complicates sexual relationships.

Stress and lifestyle changes: Stress and fatigue can quickly sap your sex drive. Stress can be from any direction in the area of;  challenging children, financial worries, ageing parents, health concerns, career woes, and more. An overload of competing demands may keep you and your partner from nurturing your relationship, sexual and otherwise.

Source Tribune