|It is defined as a clinical condition which is characterized by narrowing of blood vessels due to excess contraction of muscular wall of the vessels. The medicine that causes constriction of blood vessels is known as vasoconstrictors. Generally vasoconstrictors are given to increase the blood pressure. Vasoconstriction occurs due to the high concentration of calcium in vascular smooth muscle.A journalÂ is aÂ periodical publicationÂ intended to further progress ofÂ science, usually by reporting newÂ research. Most journals are highly specialized, although some of the oldest journals publish articles, reviews, editorials, short communications, letters, andÂ scientific papersÂ across a wide range of scientific fields. Journals contain articles that peer reviewed, in an attempt to ensure that articles meet the journal's standards of quality, and scientificÂ validity. Each such journal article becomes part of the permanent scientific record.