healthy house institute

4 Free HHI Books:

Creating a Healthy Household, The Healthy House Answer Book, Healthy Home Building, The Healthy House 4th Edition
Your email will only be used as described in our Privacy Policy

Follow us on Twitter



Proud Supporter of:




Multiple Chemical Sensitivity (MCS)

By HHI Staff

Since World War II, increasing numbers of people have become ill with a host of baffling symptoms. For example, joint pain, mental confusion, digestive complaints, and skin rashes may be reported by a single individual, while others report their own set of seemingly unrelated problems. To make diagnoses difficult, the common tests that are frequently used to determine the nature of many medical conditions are often unable to provide any sure indication of what these people have, or why they have it.


article continues below ↓

We do not strictly control Google ad content. If you believe any Google ad is inappropriate, please email us directly here.

Because of this, much of the medical community has dismissed those unfortunate enough to have such mysterious complaints, labeling them hypochondriacs, neurotics, menopausal, temporarily suffering an unusual manifestation of stress, or just plain flaky. However, this does not mean it is not a real medical condition. It simply means that it has not yet been validated by the mainstream medical establishment. After all, in the not-too-distant-past, common conditions such as premenstrual syndrome (PMS), post-partum depression, impotence, epilepsy, and depression weren’t believed to have a physical cause.


At the same time, it should be noted that patients complaining of several simultaneous symptoms were first described decades ago in a 1962 ground-breaking book, Human Ecology and Susceptibility to the Chemical Environment, by Theron G. Randolph, M.D. This physician did not arbitrarily dismiss his patients’ complaints as delusional. Instead, he believed that the varied effects were due to one general cause—the effect of exposure to low levels of chemicals in the home, at the workplace, and in food. Randolph termed the condition Ecological Illness. A growing number of other health professionals have since agreed with Randolph’s assessment.


Since the publication of Randolph’s first book, Ecological Illness has been called by a number of other names—Twentieth Century Disease, Total Allergy Syndrome, Chemical Allergies, Chemical Sensitivity, and Chemical Hypersensitivity. Currently, the most widely accepted term is Multiple Chemical Sensitivity, or MCS.


By the way, it’s suspected that at least some cases of Chronic Fatigue Syndrome (severe and persistent tiredness), Fibromyalgia Syndrome (chronic muscle and joint pain with fatigue), and Sick Building Syndrome (various symptoms temporarily exhibited by certain persons when inside a particular building) may be forms of MCS—or at least related somehow. Interestingly, the book, Chemical Exposures: Low Levels and High Stakes, by occupational medicine researchers Claudia S. Miller and Nicholas A. Ashford, provides compelling evidence for an entirely “new theory of disease.” Termed TILT (toxic induced loss of tolerance), they contend it may actually be the originator of a number of the above medical conditions, as well as others.

The Nature of MCS

Now, let’s focus in on Multiple Chemical Sensitivity (MCS). What exactly is it? Despite the many reported symptoms, MCS is generally considered (by at least some experts) to be a single condition: one that results from chemical injury. Unfortunately, to explain how toxic chemicals could so variously affect certain individuals, the specific physiological/biochemical theories are generally written in complex medical language, which can be difficult for most of us to comprehend.


However, to put it very simply, our bodies frankly haven’t had enough time to adapt as lifeforms that are able to successfully coexist with the tens of thousands of chemicals with which we now surround ourselves—compounds which never existed before in human history. We know that trees in Germany’s Black Forest have turned brown and sickly from acid rain, that great numbers of fish in the Great Lakes have tumors, and that certain bird species now lay thin-shelled eggs that break before chicks ever hatch. All these are fellow lifeforms that are unable to thrive within polluted environments. Why do we think humans are exempt?


Many of you may be wondering, “Why do some people get MCS, or some other serious condition, while others seem to be doing okay?” The answer is, we are never all equally susceptible. A particular individual’s MCS susceptibility is due to a number of factors including age (the very young and the very old have less-functional immune systems), other previous or presently existing medical conditions (those with allergies or bacterial, viral, or fungal illnesses have already-compromised immune systems), poor nutrition, stress, work exposure (those employed in petrochemical industries, those involved with pesticides, or those who work in sick buildings), genetic make-up (some individuals just have stronger constitutions than others), your home’s proximity to toxic-waste sites—and just plain luck. One person might acquire MCS as the result of a one-time toxic event, while others may acquire it as the result of an accumulation of small exposures over several years.


Often, persons with MCS report initially becoming ill after they moved into a new house, mobile home, or apartment. Those living in older buildings, might report a feeling of sickness following the installation of new kitchen cabinets or living-room carpeting. MCS has also been associated with painting a master bedroom, newly-applied termite treatments—or with any other major or minor chemical exposure in the home, at work, or at school.


Some who have MCS have noted that, at first, it seemed they simply had the flu. However, unlike the flu, the achiness, tiredness, and general malaise did not go away within the expected week or two—and their former sense of well-being never returned. Instead, the sense of being “under the weather” lingered, then progressed into a variety of new symptoms.


Whatever the ultimate cause, an affected individual may soon find that he or she now feels sick around perfume, typical cleaning products, cigarettes, gas heat, vinyl, new clothing, etc. In many cases of MCS, the number of intolerable substances tends to increase, while at the same time, the level of exposure capable of producing symptoms decreases. This effect is known as increased sensitivity or hypersensitivity. Some individuals also find that they’ve acquired food allergies or an intolerance to electromagnetic fields (EMFs). In severe cases of MCS, a great many synthetic materials, or even natural items, will provoke a multitude of symptoms if inhaled or ingested.


You should be aware that each individual with MCS has his or her own set of unique symptoms—each symptom having its own degree of severity and duration. These particular symptoms can manifest themselves physically, psychologically, or both. This shouldn’t be seen as odd or remarkable—many petrochemicals are actually neurotoxic and affect the brain. Interestingly, some MCS complaints mimic already-established medical conditions such as arthritis. Actually, MCS symptoms have been associated with virtually every organ, body system, or mind function. The following is a limited list of some reported symptoms:


Nausea, headache, hives, insomnia, depression, anxiety, gastrointestinal problems, urinary tract inflammation, menstrual irregularities, sinus inflammation, respiratory distress, heartbeat irregularities, mental confusion, chemical hypersensitivity, loss of coordination, memory impairment, joint pain, tremors, muscle aches, blurred vision, sensitivity to light, ringing in the ears, changes in normal perspiration, and anaphylactic shock.

Mainstream Response to MCS

Today, several million people in the United States have symptoms both severe and persistent enough to be called Multiple Chemical Sensitivity (MCS). This illness is increasingly being recognized by state and federal authorities as a legitimate medical condition. For example, MCS has been included in the U.S. Social Security Administration’s Social Security Income Benefit guidelines.


However, despite the growing numbers who are affected, some government recognition, and books such as those by pioneer Theron Randolph, M.D. and researchers Nicholas Ashford and Claudia Miller, some physicians remain unfamiliar with MCS; others simply dismiss it as not being a “real” medical condition. Actually, the lack of positive help MCS patients commonly receive from doctors, while discouraging, is understandable. After all, it was probably never studied (at least seriously) in medical school, nor treated during medical training, nor written much about in medical journals, nor spoken about at conferences, nor discussed openly with colleagues. And pharmaceutical salesmen don’t offer physicians samples of drugs or devices to treat MCS.


It should also be recognized that much of the medical community tends to be relatively traditional or conservative. This may be surprising to many, but it’s the reality in most of the medical world. And it isn’t just out of fear of malpractice lawsuits. Accepted medical knowledge, as with most other fields, often changes though slow adaptation—not rapid revolution. It’s not uncommon for decades to pass between the time new information, procedures, drugs, and practices are first proposed and the time they’re routinely implemented by local family physicians. Doctors with busy schedules can read, absorb, and change only so much. It’s not too surprising, then, that highly touted drugs or surgical techniques promising dramatic results with straight-forward, easy-to-understand illnesses, are far more likely to generate interest, than MCS with all its vagaries and uncertainties.


At the same time, it also appears that some physicians and major medical associations are simply adamantly opposed to the concept that everyday chemical exposures can cause negative reactions—in spite of increasing evidence to the contrary. These doctors believe there isn’t enough proof (double-blind studies, convincing medical tests, etc.) to show that MCS is anything but a dramatic fear of chemicals in any form. In fact, some of them believe there never will be proof. With physicians holding this narrow viewpoint, it is quite unlikely that they will be open to changing their minds. Remember, there are headstrong people in every profession. The medical community is no different.


(Note: The views expressed in this article are those of the author, and do not necessarily represent those of The Healthy House Institute, LLC.)


HHI Error Correction Policy

HHI is committed to accuracy of content and correcting information that is incomplete or inaccurate. With our broad scope of coverage of healthful indoor environments, and desire to rapidly publish info to benefit the community, mistakes are inevitable. HHI has established an error correction policy to welcome corrections or enhancements to our information. Please help us improve the quality of our content by contacting with corrections or suggestions for improvement. Each contact will receive a respectful reply.

The Healthy House Institute (HHI), a for-profit educational LLC, provides the information on as a free service to the public. The intent is to disseminate accurate, verified and science-based information on creating healthy home environments.


While an effort is made to ensure the quality of the content and credibility of sources listed on this site, HHI provides no warranty - expressed or implied - and assumes no legal liability for the accuracy, completeness, or usefulness of any information, product or process disclosed on or in conjunction with the site. The views and opinions of the authors or originators expressed herein do not necessarily state or reflect those of HHI: its principals, executives, Board members, advisors or affiliates.

Multiple Chemical Sensitivity (MCS):  Created on June 1st, 2008.  Last Modified on February 27th, 2011


We do not strictly control Google ad content. If you believe any Google ad is inappropriate, please email us directly here.



Information provided by The Healthy House Institute is designed to support, not to replace the relationship between patient/physician or other qualified healthcare provider.

Education Partners



Popular Topics: Air Cleaners & Air Purifiers | Allergies & Asthma | Energy Efficiency & Energy Savings | Healthy Homes | Green Building
Green Cleaning | Green Homes | Green Living | Green Remodeling | Indoor Air Quality | Water Filters | Water Quality

© 2006-2018 The Healthy House Institute, LLC.


About The Healthy House Institute | Contact HHI | HHI News & Media | Linking Resources | Advertising Info | Privacy Policy | Legal Disclaimer


HHI Info