Here are a few ways this can happen.
1. Cardiac Arrest
A study conducted by a leading American medical journal has revealed that each additional hour of sexual activity per week resulted in an increased risk of 2-3 myocardial infarctions (heart attacks) and one sudden cardiac death per 10,000 person.
Experts say that indulging in sexual intercourse can trigger a subarachnoid haemorrhage i.e. is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain via the Valsalva maneuver. The Valsalva maneuver is performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one's mouth, pinching one's nose shut while pressing out as if blowing up a balloon.
A study also found that the "deceased is usually married; he is not with a spouse and in unfamiliar surroundings," and death usually occurs after "a big meal with alcohol." So, men who were unfaithful were significantly more likely than those who were faithful to experience severe or fatal cardiac events during sex. A related study seemed to support the death during extramarital sex theory. Fourteen of the 20 cases of coital death, happened during an affair. "Dying in the saddle" is another popular euphemism for death during sex.
4. Sex Drugs
Viagra use has been linked to sudden cardiovascular death during sexual activity among elderly or otherwise infirm men. Researchers also say that prescription or recreational drugs, such as cocaine can also possibly contribute to unexpected deaths during consensual sex.
5. Unprotected Sex
I you are having unprotected sex with multiple partners will kill you suddenly, There are lot sexual diseases like HIV, STD that make kill you . The Human papillomavirus (HPV) was once believed to have no effect on men, but it’s now found to be harmful to men as well as well as women.