Definition & Description

“MCS is a disorder in which a person develops symptoms from exposure to chemicals in the environment.” Based on personal experience, I would add to that definition my belief that everyone has symptoms from exposure to chemicals. Most just don’t realize it. They seek treatment and get a diagnosis for a variety of other diseases, maladies, and conditions. People who claim to have MCS as a disorder are seeking to get at the root of their symptoms and have come to identify exposure to chemicals as the source.
Basically, chemical sensitivity is when a person begins developing negative reactions to chemicals in their lives. These reactions can be anything from irritating and sporadic to debilitating and chronic. They include physical and/or mental impairments that may be annoying or disabling. In a nutshell, a person is exposed to a chemical or chemicals which "triggers" a reaction. Future exposure(s) then causes reactions that can be more in frequency and/or intensity. In addition, triggering from exposure to one chemical can lead to reactions from exposure to other chemicals. If that sounds confusing, think of a pebble dropping into water and the rings that form. That would be one exposure and a reaction. Now imagine multiple pebbles dropping and the rings that form from each. Some overlap.The ones closest together create large and more pronounced rings. Even the ones far away from each other create a large "wave" when the outer rings meet. Well, your body is the water and the pebbles are the chemicals. The rings are your body's reactions. Each of us has a toxic load that our bodies can handle that is determined by our unique genetic makeup. Currently, there are 91 chemicals in the average person's body. That's 91 pebbles hitting your body and 91 rings or reaction. I believe some people are more alert than others to the pebbles hitting and sense the rings forming.Those people are called "sensitive." I actually like that. Those of us who are "sensitives" know when there is a disturbance in the environment and our bodies tell us in profound ways.
Resources for learning more about MCS
Chemical Poisoning- General Principles of diagnosis and treatment from Dr. Myhill
Chemical Sensitivity Questionnaire
The Dispossessed; Living with Multiple Chemical Sensitivities Book Review
A 4-year old Girl with Manifestations of Multiple Chemical Sensitivities
Handbook of Environmental Psychology
Health Tomorrow at Contaminated Without Consent
I Have MCS by Gillian McCarthy
Multiple Chemical Sensitivities: How It Is Manifested
People With Multiple Chemical Sensitivities Fight To Be Believed
Public Health Assessment Guidance Manual ATSDR Community Matters
The Toxins That Threaten Our Brains