It is normal for a man to have five to six erections during sleep, especially during rapid eye movement (REM). Prescribed drugs used to treat high blood pressure, ulcers, depression, and prostate cancer, as well as medications to prevent baldness or aid in dieting, can have side effects that include impotence.
More drastically, inflatable or rigid penile implants may be fitted surgically. This device works quite well, although some men complain about the discomfort of the elastic ring in addition to the hassle of, well, pumping up. John Brinkley initiated a boom in male impotence cures in the U.S.
Modern public health
Given the advances in medicine and nutrition research, however, it is no longer a scary thing. The current diagnostic and statistical manual of mental diseases (DSM-IV) has included a listing for impotence.
Men with secondary impotence are typically able to engage in intercourse only 25% of the time. Given the advances in medicine and nutrition research, however, it is no longer a scary thing. During the late 16th and 17th centuries in France, male impotence was considered a crime, as well as legal grounds for a divorce.
The practice of vaccination became prevalent in the 1800s, following the pioneering work of Edward Jenner in treating smallpox. James Lind's discovery of the causes of scurvy amongst sailors and its mitigation via the introduction of fruit on lengthy voyages was published in 1754
Public health - early roots
Public health has early roots in antiquity. From the beginnings of human civilization, it was recognized that polluted water and lack of proper waste disposal spread communicable diseases (theory of miasma).
The focus of a public health intervention is to prevent and manage diseases, injuries and other health conditions through surveillance of cases and the promotion of healthy behaviors, communities and environments. Many diseases are preventable through simple, non-medical methods. For example, research has shown that the simple act of hand washing with soap can prevent many contagious diseases. In other cases, treating a disease or controlling a pathogen can be vital to preventing its spread to others, such as during an outbreak of infectious disease, or contamination of food or water supplies. Public health communications programs, vaccination programs, and distribution of condoms are examples of common public health measures. Measures such as these have contributed greatly to the health of populations and increases in life expectancy.