MCS–Possible Symptoms

Nothing on my website should be construed as medical advice.  I am not a doctor.  I am only a person with severe MCS who has done a lot of research, “paid attention” to my experiences, and followed the good advice of those who have gone before me (with good results). 

Symptoms of MCS can mimic other diseases and illnesses.

The main distinguishing characteristic of MCS is that symptoms appear upon exposure to chemicals and they get better when the chemical is removed.


  1. Sometimes you have to be paying attention to notice this.
  2. Sometimes physical reactions are delayed (and NOT immediate), AND
  3. The “baseline” of chemicals in the current environment can “skew the results” of your observations, especially if the “baseline” of chemicals is moderate to high.

Symptoms can come and go, especially depending on exposure to chemicals.  Sometimes detoxing can cause “symptoms,” especially if one tries to detox too fast (like using “sauna treatments” too often).

Symptoms vary from mild to completely disabling.  Many times, severe MCS is “only” miserable, but it can also be fatal.

People with MCS can have a huge variety of symptoms.  Here are some:

  • irregular heartbeat
  • tachycardia/elevated resting and walking heartbeats
  • palpitations
  • fatigue, ranging from mild to so severe that it is difficult to describe.   [Here’s my best effort at describing severe fatigue:  Imagine that you have just run a marathon.  You come to the end and someone says, “You must run another mile!”  So you dig down deep and run some more.  “Hurry!” they say.  Your heart is racing so fast that it’s a little scary.  “Another mile now!”  You push and push until you literally have nothing left.  You are so tired you sink down onto the ground.  You cannot even speak because you are so tired.  It almost takes an effort to breathe.  This is what I face if I am exposed to too many chemicals for too long (especially mold) and/or push myself too much.  Not fun.  I’ve learned to try to stay away from that edge and rest when I need to.]
  • headaches, ranging from mild to migraine/disabling
  • ophthalmic migraines or other visual disturbances
  • nosebleeds (I don’t suffer these, but many people do.)
  • muscle pain, aches, cramping, and/or “fibromyalgia,” sometimes severe, sometimes VERY severe
  • sensitivity to light, sound, touch, and/or movement
  • nausea, dry heaves/vomiting
  • persistent heartburn and/or indigestion/bloating
  • intolerance to certain foods (temporary or long-term)
  • constipation, diarrhea, or alternating
  • tingling
  • extremities “falling asleep”  (some even report paralysis, though I have never had that)
  • sudden tremors, kind of like Parkinson’s, only these tremors come with exposure to certain levels of chemicals and disappear completely when the person is removed from the chemical environment; for me, usually accompanied by brain fog
  • seizures (I have not had any, praise God)
  • vertigo (sometimes extreme)
  • swelling
  • weakness, sometimes sudden but can also be chronic
  • periods of inability to get warm
  • sleep apnea (new or worsening)
  • severe sleep problems
  • frequent nightmares
  • brain fog
  • inability to think clearly [BAD brain fog, like “I know something’s wrong right now (i.e. I’m reacting to a new chemical that just popped up) but I can’t think what to do.”]
  • drugged-like feeling (The closest thing I know to compare it to is the “post-C-section drugs” they gave me)
  • loss of memory
  • ADD (new or worsening)
  • “dog nose” (can smell molecules no one else can—minute amounts and/or from miles away)
  • Reactive Airway Syndrome or occupational asthma (for which the only treatment not causing damage over time is removal of the triggering chemical/toxin)

Many with MCS also have allergies.  (Allergies are COMPLETELY different from MCS.  They are immune-related, whereas MCS is toxin/poisoning-related.)

(I hardly suffer at all from allergies, but for some people, having both MCS and allergies can be a BIG problem.)

I hope that by sharing these symptoms, if you have MCS, you can know you are not the only one with these problems.