MCAS is a condition where certain immune cells, called mast cells, are overactive.

Normally, mast cells release chemicals like histamine to help your body respond to threats.

In MCAS, these cells release too much, too easily, often in response to things that wouldn’t normally cause a reaction.

MCAS can show up in lots of ways, and it looks different for everyone. Some common signs include:

Flushing or rashes

Hives or itching

Swelling in different parts of the body

Digestive issues like bloating, cramps, or nausea

Headaches or brain fog

Fatigue that doesn’t improve with rest

Feeling extra sensitive to foods, chemicals, or temperature changes

Triggers vary from person to person, but some common ones include:

Certain foods or food sensitivities

Environmental allergens like pollen, dust, or mold

Medications, additives in medications

Introducing something new into your supplement or medication regime

Temperature changes

Stress or mood changes

Mast cells are found throughout connective tissue, and hEDS affects connective tissue.

This means the way mast cells behave may be influenced in people with hEDS.

Many people with hEDS notice symptoms that overlap with MCAS, like rashes, digestive issues, or flares after triggers.

MCAS can make your body feel unpredictable, but you don’t have to just “live with it.”

By understanding how your body systems are connected and building strategies that fit your lifestyle, you can reduce flares and feel more steady.

To read more of my MCAS strategies check out this blog post