|Sleep dysfunction is also known as sleep disorder or somnipathy, it is a medical disorder. Sleep dysfunction effects normal physical, mental, social and emotional functioning of humans. This is normal disorder and usually temporary, may be caused due to stress or other factors. Sleep dysfunction is of many types which include dysomnias, parasomnias, circadian rhythm sleep disorders insomnia and sleep apnea. Journal Article is sometimes called a Scientific Article, a Peer-Reviewed Article, or a Scholarly Research Article. Together, journal articles in a particular field are often referred to as The Literature. Journal articles are most often Primary Research Articles. However, they can also be Review Articles. These types of articles have different aims and requirements. Sometimes, an article describes a new tool or method. Because articles in scientific journals are specific, meticulously cited and peer-reviewed, journal databases are the best place to look for information on previous research on your species. Without a background in the field, journal articles may be hard to understand - however, you do not need to understand an entire article to be able to get valuable information from it.