Everyone thinks an orgasm is the best thing ever because it causes pleasure and satisfaction like no other, but there are some other words that describe getting off for some, and they aren’t so great.

A typical orgasm, the peak physical reaction to sexual stimulation, can include whole-body and pelvic sensations as well as flushing, increased heart rate, and blood pressure, and heavy breathing, the researchers say. Psychological effects can include feelings of happiness, love, and relaxation.

But according to a new report in Sexual Medicine Reviews, lots of negative side effects that can be triggered by an orgasm, too. Like these…

The sudden feeling of weakness that occurs with orgasms is a real thing. It’s called “orgasmolepsy,” and it was first reported back in 1928. Symptoms typically last for less than 30 seconds and include a complete loss of muscle control.

1. Sickness
Imagine getting flu-like symptoms after sex. When this happens it’s called post-orgasm illness syndrome, and it’s a constellation of symptoms that have been reported in men after ejaculation, including severe fatigue, intense warmth and a temporary flu-like state.

Apparently, your body mislabels proteins in your own semen as foreign invaders, which ramps up your immune response and makes you feel sick. Post-orgasm illness syndrome can be difficult to diagnose, but if you think sex is linked to your symptoms, make an appointment with an allergist, says Mohit Khera, M.D., M.P.H., a urology professor at Baylor College of Medicine. That can help ID a semen allergy.

2. Hallucinations
You can literally take your partner out of this world while having sex and we aren’t talking about using any drugs to enhance the experience here. Of nearly 50 women who claimed to have an “expanded sexual response,” 76 to 100 percent noted a flying experience or sensation of flight after they had an orgasm, according to a 2011 study from Turkey.

What’s even crazier is that up to 24 percent noted a sense of entering a cartoon world, up to 75 percent noted a feeling of leaving their bodies, and up to 24 percent listed déjà vu, too.

3. Weakness
The sudden feeling of weakness that occurs with orgasms is a real thing. It’s called “orgasmolepsy,” and it was first reported back in 1928. It usually occurs in connection with narcolepsy or other sleep disorders. Symptoms typically last for less than 30 seconds and include a complete loss of muscle control.

Researchers aren’t sure what causes it, but they believe firing of the amygdala response, coupled with hypocretin deficiency, which occurs with narcolepsy, may be to blame.

There have been reports that link sneezing to sex since the 1900s. One from 1972 detailed a 59-year old man who developed severe sneezing and a runny nose after orgasm, which continued for 10 years.

4. Crying
Have you ever hooked up with someone who cried afterward? Bawling after sex is a symptom of something called postcoital dysphoria, a constellation of after-sex effects that include tearfulness, melancholy feelings, depression, anxiety or agitation. They can appear up to an hour after sex and often occur in stable relationships, researchers say.

Nearly 1 in 3 female university students reported experiencing at least one symptom of postcoital dysphoria at least once, according to a 2011 study in the International Journal of Sexual Health. It can be alarming to see your partner get emotional after getting it on, but it might just be a biological reflex to the hormonal and neurological sensations that occur with it, says Lori Brotto, Ph.D. Or she may feel lonely after the intimacy of sex is over.

5. Sneezing
Sneezing after sex? What the hell? There have been reports that link sneezing to sex since the 1900s. One from 1972 detailed a 59-year old man who developed severe sneezing and a runny nose after orgasm, which continued for 10 years.

Researchers believe that activating one part of the parasympathetic nervous system during orgasm may actually trigger a different branch of it, too, which sparks your sneezing symptoms.

6. Headache
Headaches caused by orgasm belong to the type two category of headache: Those which are bilateral, explosive and triggered by some kind of excitement.

The duration of orgasm headaches can range from several minutes to three hours and may be alleviated with anti migraine meds or pretreatment with propranolol.

7. Pain
Pain with orgasm can occur in women, and we aren’t talking about pain from your big d size, either. A 2009 study described three cases of women who experienced it, even without any anatomical or infectious causes of pain.

Guys aren’t left out of this scenario, either. Men with chronic prostate disease have also been known to experience pain with orgasm.

8. Foot sensations
According to a 2013 case report in the Journal of Sexual Medicine, a 55-year-old woman complained of “undesired orgasmic sensations” that originated in her left foot, which was the same feeling as when she was having sex with her husband. Sounds kind of cool, right?

In fact, whenever she experienced a vaginal or clitoral orgasm, she felt the same sensation in her left foot afterward. The researchers believe it may be due to partial regeneration of damaged nerve fibers in her foot. Lucky broad.

Photo: iStock/VikaValter