Define Sclerosis

According to the Medical Dictionary at thefreedictionary.com, sclerosis is defined as: "an induration or hardening, especially from inflammation and in diseases of the interstitial substance; applied chiefly to such hardening of the nervous system or to hardening of the blood vessels."

In Plants As Well As People

• Reference.com's dictionary offers us another version of sclerosis--one from the world of botany (or the science of plants). Similar to the definition for humans, in botany it is defined as "a hardening of a tissue or cell wall by thickening or lignification" (or becoming woody or wood-like).

A Well-Known Sclerosis

• You most likely recognize the term "sclerosis" from multiple sclerosis, which affects 205 million people worldwide, according to WebMD. Four hundred thousand of those suffering from the disease are Americans. Multiple sclerosis, or MS, is a disease that affects the brain and spinal cord and results in the loss of muscle control as well as vision and balance loss. It can also cause numbness. The nerves in the brain and spinal cord are assaulted and damaged by the body's own immune system, which normally targets and destroys things foreign to the body such as a virus, but instead attacks normal tissues. Scientists are testing a vaccine that appears to help halt the progression of MS.

Another Sclerosis

• Amyotrophic lateral sclerosis, or ALS, is a disease in which nerve cells in the brain and spinal cord slowly die. It is also called Lou Gehrig's disease. The nerve cells affected are motor neurons, the cells that control the muscles and allow you to move. People with ALS gradually become disabled and breathing becomes difficult, as does eating. It eventually leads to death and currently has no cure. ALS is, fortunately, more rare than MS.

A Lesser-Known Sclerosis

• Tuberous sclerosis complex is one you may not recognize. It is a genetic disorder that causes tumors to form in different organs. These tumors develop primarily in the brain, eyes, heart, kidney, skin and lungs. The disorder affects some severely, and others have such mild cases that they are never diagnosed. The range runs from the severely mentally retarded to healthy working professionals such as doctors. According to the tsalliance.org website, around 1 million people worldwide are known to have tuberous sclerosis, and about 50,000 of those live in the United States. TSC also has no cure.

Other Sclerosis

• -arterial sclerosis
  -bone sclerosis
  -diffuse cerebral sclerosis
  -glomerular sclerosis
  -sclerosis of the liver
  -systemic sclerosis
  -endplate sclerosis
  -subchondral sclerosis