Autoimmune diseases—which occur when the immune system turns on you and starts attacking healthy cells—can impact anyone, but almost 80 percent of people who have them are women. No one knows exactly why, but recent research suggests that it may have to do with differences in the way certain genes are expressed in females. Whatever the cause, it's especially bad news since autoimmune illnesses are on the rise. "In the past 50 years, the incidence of autoimmunity in the US has tripled," says Dr Amy Myers, an expert in functional medicine.

There are at least 80 different autoimmune diseases. Though each one is unique, many share hallmark symptoms, such as fatigue, dizziness, low-grade fever and inflammation, which can cause redness, heat, pain and swelling.

Treatment depends on the disease, but it often includes anti-inflammatory medications, drugs that suppress the immune system, or newer biologic agents that either mimic substances normally produced by the body or block other substances that are part of the immune system, explains rheumatologist Dr Howard Smith. Natural strategies are also gaining traction, including reducing inflammatory foods like those high in sugar and saturated fat, reducing stress, lowering your burden of toxins and healing your gut. As Dr Myers notes, 80 percent of your immune system is located in your gut.

Catching autoimmune diseases early is the best way to slow their progression, but you need to know what to look for. Read on to learn the signs and symptoms of seven the most common ones: