Hand hygiene or simply hand washing is the act of washing hands with soap and water with the intention of removing debris, dirt, grease, microorganisms or other harmful or unwanted substances.  Hand drying is part of hand hygiene as wet hands are easily recontaminated.  If soap or water is not available, a hydroalcoholic gel that has at least 60% (v / v) alcohol can be used, unless extremely dirty or greasy hands.   Hand hygiene is essential to prevent the spread of infectious diseases. 
The discovery of the effectiveness of hand hygiene is credited to the Hungarian doctor Ignaz Semmelweis, who in 1846 introduced a hand washing system at the Vienna General Hospital to prevent cross infection; his findings led to a decrease in mortality from puerperal fever.  Years later, British nurse Florence Nightingale pioneered mandatory medical hygiene in the field hospital where she worked, in the middle of the Crimean War. 
The installation of running water, sanitation and sewerage has been vital in promoting hand hygiene in the home. Before the extension of the tap or faucet in the houses, this activity was carried out in other mobile furniture such as sinks, jugs or basins with spillway, where water was poured with a jug.
Despite these systems, there are developing or underdeveloped countries where the supply of piped water is not sufficiently extended. According to Unicef, each year more than 300,000 children under the age of five die from diarrheal or infectious diseases linked to poor sanitation, and many of these deaths could have been prevented through proper hand hygiene. To raise awareness, the UN agency has been promoting "World Handwashing Day" since 2009. 
In 2020, during the coronavirus pandemic, the World Health Organization recommended hand washing as one of the ways to prevent infection.   It is even much more effective in the case of the non-population. infected than wearing gloves. 
Washing hands with soap and water is a measure of personal hygiene that prevents the spread of many diseases, both those transmitted by the fecal-oral route and infectious, which can be passed if someone with dirty hands touches cavities such as the eyes , nose or mouth. The five key times to wash your hands with soap are: after a bowel movement; after cleaning a baby's bottom; before feeding a child; before and after preparing food, and before and after eating. 
If soap and water are not available, a hand sanitizer gel that contains at least 60% alcohol can be used. However, household disinfectants are not as effective in certain situations. 
Medical hand hygiene refers to hygiene practices related to sanitary procedures. In this case, the main objective is to protect patients from pathogens and chemicals that can cause harm, preventing health care-related diseases and infections. 
According to Unicef, hand hygiene with soap and water has the following benefits: 
Minimizes the spread of diseases transmitted by microorganisms.
Prevents the spread of diseases transmitted by the fecal-oral route.
Reduces the rate of acute respiratory infections.
The infant mortality rate in home births decreases Throughout the twentieth century, the different agencies of the United Nations Organization have carried out awareness campaigns on properly washing hands with soap and water, especially in countries in the process of