CTD is not so much a disease as it is a response to excessive demands that we place on our bodies - without giving them adequate time to recover between. A problem that interferes with the normal body processes. To function, or work properly, the body and each of its parts need a steady supply of blood, rich in oxygen and nutrients . Nutrients are the things that make up the fuel of the body - glucose for example. Cutting off or slowing the blood supply harms the tissues of the body.
Tense muscles can actually squeeze off their own flow of energy and fuel.
This chemical can be a potent pain causing chemical. Lactic acid is probably the chemical that produces the burning feeling when muscles are over-exercised. As pain develops muscles tighten even further because they attempt to guard the surrounding area. Guarding is a term that is used to describe a reflex that all muscles in the body share. As a result blood flow is slowed down even more.