person wearing a mask surrounded by multiple chemical fumes

The Reality of Multiple Chemical Sensitivities (MCS)

Certain chemicals, like asbestos and tobacco smoke, are known to be toxic and to cause illness. But some people are sensitive to many other things in the environment. This is a condition known as multiple chemical sensitivities (MCS).

People with MCS may develop unpleasant symptoms when they are exposed to substances found in things like:1

MCS may be called an “environmental illness” or “multiple environmental chemical sensitivities.”2

How does MCS start?

Doctors think MCS may be triggered by a single exposure to a toxic substance like a pesticide. Once this initial exposure occurs, low levels of chemicals found in the common substances can set off symptoms in certain people.1

Who gets MCS?

About 25.6 million adults in the United States have been diagnosed with MCS. Around 71 percent of people with MCS are asthmatic.2

Symptoms of multiple chemical sensitivities

Low levels of substances can cause symptoms that range from headaches and asthma to fatigue, and muscle and joint pain. Rashes, confusion, and memory loss can also be the symptoms of MCS.1

A controversial diagnosis

A painful reality for those living with MCS is that some doctors do not feel that MCS is a physical illness. Rather, some doctors believe MCS may be related to mental health instead of physical health.3

Chronic pain syndromes, such as fibromyalgia and chronic fatigue syndrome, may occur more frequently in those with MCS. Those living with chronic pain have an increased risk for mental health disorders, such as:3

  • Depression
  • Anxiety
  • Substance use disorders

This does not mean MCS is all in your head. In fact, this may add to the complication of diagnosing this condition. It is hard enough to deal with a condition that may trigger your asthma symptoms. To have others doubt you may be even more difficult. If you are living with MCS, it is a real condition that has real symptoms.

Many doctors believe that there needs to be better testing available to help them diagnose MCS. Exposure to different chemicals and how a person reacts to those chemicals may be helpful for the future testing needs of this condition.4

MCS and its deep impact

People with MCS may not be able to access restrooms, businesses, workplaces, and public places due to a risk of disabling symptoms. Fragranced cleaning, air fresheners, and beauty products are the biggest culprit of asthma triggers. Research shows that more than 22 million Americans have missed work due to exposure and asthma-related symptoms.2

Finding a doctor

If you have been diagnosed with MCS or think you may have it, finding a doctor with knowledge of the condition will be important. This may not always mean to “shop around.” You can start with your doctor. Give them information about MCS and a history of your condition. Make sure to write down details of exposures, symptoms, and other things that may be important.

A second opinion from another doctor does not mean you do not trust the opinion of the first doctor. Sometimes you need to advocate for your health, especially with conditions like MCS that are difficult to diagnose.

More research is needed

More research is needed to find the causes, risks, and treatments best for MCS. You are not alone in your path to finding a diagnosis. There are many more people like you who have asthma and MCS. Advances in tests and treatment may finally provide answers to this mysterious condition.4 Certain chemicals, like asbestos and tobacco smoke, are known to be toxic and to cause illness. But some people are sensitive to many other things in the environment. This is a condition known as multiple chemical sensitivities (MCS).

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