Understanding Muscle Relaxers and Their Effects

A muscle spasm is different than a muscle twitch. A muscle twitch or fasciculation is uncontrolled fine movement of a small segment of a larger muscle that can be seen under the skin.

Muscles are complex structures that cause movement in the body. There are three types of muscle in the body:
   - heart muscle that pumps blood (cardiac muscle)
   - skeletal muscle that moves the external body parts
   - smooth muscle that move portions of hollow structures inside the body

Spasms can occur when a muscle is overused and tired, particularly if it is overstretched or if it has been held in the same position for a prolonged period of time. In effect, the muscle cell runs out of energy and fluid and becomes hyperexcitable and develops a forceful contraction. This spasm may involve part of a muscle, the whole muscle, or even adjacent muscles.

Systemic illnesses like diabetes, anemia (low red blood cell count), kidney disease and thyroid and other hormone issues are also potential causes of muscle spasms.
Diseases of the nervous system, such as multiple sclerosis or spinal cord injury, can be associated with muscle spasm.

Muscle relaxant is a drug which affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasm and pain, and hyperreflexia. Tizanidine is perhaps the most thoroughly studied clonidine analog.