It’s cold season. The weather is hot, then the next day it’s freezing. You wake up with a headache, stuffiness, sore throat, and runny nose. Just great – you’ve caught a cold. Your doctor agrees with the diagnosis and prescribes you antibiotics for treatment. But what if you are both wrong? What if your symptoms are actually caused by mold?

The common symptoms of an upper respiratory infection – or the common cold – include stuffiness, sore throat, headache, runny nose, coughing, malaise, and loss of appetite. But these are the same symptoms, among many others, commonly caused by allergenic or toxic mold. In fact, according to Dr. Carol Kauffman, “most of these infections are caused by a fungus.”

So what’s the harm in misdiagnosis? It turns out, a lot. A doctor who mistakes a reaction to mold with an upper respiratory infection will often prescribe antibiotics to fight the cold. In fact, 75% of all the antibiotics prescribed in the United States are for upper respiratory infections. The problem is that antibiotics kill bacteria and not all bacteria are bad. That bacteria is what protects us from mold infections in the first place.

There’s a constant struggle between mold and bacteria in our bodies. This struggle is normal and we are supposed to have a certain level of mold and a certain level of mold-fighting bacteria that balance each other out. Antibiotics throw off this balance, allowing mold to gain the upper hand.

This can cause mold colonies to start growing inside you unabated, producing mold infections like skin rashes and yeast infections. Yeast infections are often the result of an overuse of antibiotics. Mold is always around us, but most healthy people have immune systems that fight off infections. Antibiotics suppress that immune system.

Antibiotics for the common cold are usually a mistake anyway. Upper respiratory infections are almost always caused by a virus, not bacteria, so the antibiotics are ineffective.