
Multiple sclerosis (MS) is a condition that affects the central nervous system, particularly the myelin sheath, the protective coating that surrounds nerve cells. When the myelin sheath is damaged, it becomes more difficult for nerve cells to “talk” to one another. As a result, messages that are normally transmitted between the brain and the rest of the body are delayed or lost.
Such messages are an integral part of sexual function. When a person becomes sexually aroused, the brain sends a message to “tell” the sexual organs to start getting ready. For men, this process triggers an erection. In women, the vagina starts to lubricate.
For people with multiple sclerosis, the messages don’t transmit properly.

Experts estimate that about two-thirds of people with MS experience sexual problems.
Research has shown that women with MS are at double the risk for sexual dysfunction than women without MS. In addition to poor vaginal lubrication, women may find themselves less interested in sex or they might have difficulty reaching orgasm. Pain may be another problem, especially if the vagina is not sufficiently lubricated.
For men, common issues are erectile dysfunction (ED) and problems with ejaculation.
MS can interfere with genital sensation in both men and women with MS. They might feel less sensation than they used to. Or, sensation might be heightened, even to the point of being painful.

Impaired message transmission is not the only cause of sexual issues for people with MS.
MS can be exhausting, and people can feel too fatigued for intimacy. Certain sexual positions might become less enjoyable or comfortable because of weakness, stiffness, or spasms in the muscles.
Psychological factors are a concern as well. Anxiety is common for people with MS, and many feel nervous about pleasing their partner, self-conscious about their body, and fearful of urinary or stool incontinence. They may also feel depressed because of the changes in their life and in their relationships.

The good news is that many of these issues can be treated. For example, there are several ways to treat ED, including pills, injections, vacuum devices, and suppositories. Women with vaginal dryness might consider using a personal lubricant. Learn more with these links:
What is erectile dysfunction (ED)? What causes ED? How is ED treated?

Couples coping with MS-related sexual changes may need to adjust their sexual routines, too. Planning ahead for sex, taking more time in the bedroom, and trying out new positions or activities can be helpful for maintaining intimacy.

Sex therapy or couples counseling are other ways to address sexual problems related to MS. For more information, please see these links:
What are sex therapists? What do they do?
How does one find a sex therapist?
What happens during sex therapy?
Resources
International Society for Sexual Medicine
“How might multiple sclerosis affect a person sexually?”
https://www.issm.info/sexual-health-qa/how-might-multiple-sclerosis-affect-a-person-sexually/
The Journal of Sexual Medicine
Gava, Giulia MD, et al.
“Prevalence and Psychopathological Determinants of Sexual Dysfunction and Related Distress in Women With and Without Multiple Sclerosis”
(Full-text. Published online: April 19, 2019)
https://www.jsm.jsexmed.org/article/S1743-6095(19)30467-9/fulltext
Zhao, Shankun MD, et al.
“Association Between Multiple Sclerosis and Risk of Female Sexual Dysfunction: A Systematic Review and Meta-Analysis”
(Full-text. Published online: November 1, 2018)
https://www.jsm.jsexmed.org/article/S1743-6095(18)31215-3/fulltext
National Multiple Sclerosis Society
“Sexual Problems”
https://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Sexual-Dysfunction
SexHealthMatters.org
“About Two-Third of MS Patients Have Sexual Problems”
https://www.sexhealthmatters.org/did-you-know/about-two-third-of-ms-patients-have-sexual-problems
“Multiple Sclerosis: Be Open to Sexual Changes”
(May 28, 2019)
https://www.sexhealthmatters.org/sex-health-blog/multiple-sclerosis-be-open-to-sexual-changes