Sometimes we stop having sex, but we didn't do it on purpose: We go through a breakup; we're traveling; our partner is sick; or a busy schedule puts our sex life at a standstill. A few days of no sex turns into weeks, and weeks turn into months, and before we realize it, we've involuntarily taken a temporary vow of abstinence. Sexual ruts happen from time to time, but a lack of sex can have significant effects on our body.

From erectile dysfunction to a weaker immune system, below are six surprising ways sexual abstinence influences our mental, emotional, and physical health.

Lower Sex Drive

If we haven't had sex in a while, there's a greater likelihood we'll start to want sex less. During sex, the body is inundated with endorphins that make us feel good, and help us associate sex with positive feelings. Abstaining from sex will lessen this connection, and therefore, reduce the need to have sex.

Psychologically speaking, all of our libido or sex drive will go somewhere else.

"Your libido can increase your career drive and manifest more successful ambitions or, if you choose, you may direct your sexual energy into your children versus intercourse," Dr. Fran Walfish, Beverly Hills family and relationship psychotherapist, author of The Self-Aware Parent, and co-star, Sex Box on WE TV, told Medical Daily.

However, no matter how long we're abstinent, Walfish says we can resume the same sexual drive, energy, and appetite we enjoyed before. She does warn, "don't expect a sudden rise in libido if you never had a high sex drive."

More Stress

A lack of regular sex can lead to an elevation of stress levels. A 2005 study in Biological Psychology found penile-vagnal intercourse, but not other sexual behavior, was associated with better mental and physical performance, and lower stress levels. People who hadn't had regular sex showed higher blood pressure spikes in response to stress than those who recently had intercourse. Here, sex serves as a coping mechanism to deal with stressful moments.

Poor Self-Esteem

A halt in our sex life can make us feel both less desired and sad. Researchers believe semen has antidepressant qualities that can counteract feelings of depression. Semen contains several hormones, including testosterone, estrogen, FSH (follicle-stimulating hormone), luteinising hormone, prolactin, and several different prostaglandins. These have been detected in women's blood within hours of being exposed to semen.

In a 2002 study in Archives of Sexual Behavior, researchers found condom use, an indirect measure of the presence of semen in women, was linked to scores on the Beck Depression Inventory. Women who were having sex without condoms were less depressed, while depressive symptoms and suicide attempts among those who used condoms were proportional to the consistency of condom use. It’s possible that semen may lessen depressive symptoms as the vagina absorbs the components of semen.

Less Intelligent

Less sex can translate to less intelligence. A 2013 study in Hippocampus found sex boosts neurogenesis — the creation of new neurons in the brain — and also improved cognitive function. This is because sexual experiences leads to cell growth in the hippocampus, a region of the brain that's vital to long-term memory. Sex could potentially help prevent deterioration that leads to memory loss, and dementia.

Weaker Immune System

We may be more prone to colds and other illness with less sex. Regular sex, in moderation, could help boost our immune systems, according to a 2004 study in Psychological Reports. Researchers evaluated how strong participants' immune systems were by measuring levels of immunoglobulin A (IgA), an antigen found in saliva and mucosal linings. IgA is the first line of defense against colds and flus, as it binds to bacteria that invade the body, and then activates the immune system to destroy them. Those who had sex more frequently showed significantly higher levels of IgA than their counterparts.

Erectile Dysfunction

Abstinence can increase the likelihood of erectile dysfunction (ED) for men. A 2008 study in the American Journal of Medicine found men who reported having sexual intercourse once a week were half as likely to develop ED as men who had sex less frequently. Researchers tracked over 900 men in their 50s, 60s, and 70s for five years, and showed regular sexual activity preserved potency in the same fashion as exercise preserved the body’s aerobic capacity.

Regular sex can reduce the risk of ED, even at old age.