The cause of fibromyalgia is unknown; however, it is believed to involve a combination of genetic and environmental factors with half the risk attributed to each. The condition runs in families and many genes are believed to be involved.
Agonist: A substance that acts like another substance and therefore stimulates an action. Agonist is the opposite of antagonist. Antagonists and agonists are key players in the chemistry of the human body and in pharmacology.
4. An agonist ties to a receptor site and causes a response whereas an antagonist works against the drug and blocks the response. 5. Agonists are also chemicals or reactions, which help in binding and also altering the function of the activity of receptors.