“The brain is the body’s most important sex organ.” This well-known phrase bears more than a little truth. Functional sex organs, appropriate hormone levels, and the ability to become sexually aroused alone don’t guarantee good sex. Other factors — brain factors — can get in the way.

Relationship issues
Tension and emotional distance can undermine a couple’s sex life. Conflicts having nothing to do with sex, like finances or child-raising issues, can be at the root of a sexual problem. It works the other way, too: a sexual issue can strain a couple’s ability to get along.

Performance anxiety
A person may become so worried about sexual performance that sex is no longer 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.

Expectations and past experiences

Your sexuality is a natural drive that’s with you from birth, but your family, culture, religious background, the media, and your peers shape your attitudes toward 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 hit from any direction — challenging children, financial worries, aging parents, health concerns, career woes, and more. An overload of competing demands may keep you and your partner from nurturing many aspects of your relationship, sexual and otherwise.

To learn more about how sex changes with age and how to realize the full potential of later-life sex, read Sexuality in Midlife and Beyond, a Special Health Report from Harvard Medical School. This report will take you through the stages of sexual response and explain how aging affects each. You’ll also learn how chronic illnesses, common medications, and emotional issues can influence your sexual capabilities. Finally, you’ll find a detailed discussion of various medical treatments, counseling, and self-help techniques to address the most common types of sexual problems.