It could come on at any age. Alopecia areata tends to appear during childhood, but it could surface at any age. It can also disappear for decades. It's common to have it as a kid, have it go away, and then have it come back 20 years later.
It's asymptomatic. Apart from the loss of hair, alopecia areata doesn't cause headaches, irritation, or other symptoms. If the hair loss occurs on the back of the head, some people don't even realize it's there until someone else points it out for them.
The hair loss isn't permanent. Unlike age-related or natural baldness, alopecia areata does not damage your hair's ability to grow back. Your immune cells come in and surround hair follicles like a swarm of bees, which stops them from producing hair. But once your immune system settles down, hair often grows back just as before.
Stress is a major trigger. Stress triggers inflammation. So if you suffer from alopecia areata—or any other autoimmune disease—stress can launch or heighten your hair loss. For this reason, exercise, meditation, and other stress-relief therapies can calm or prevent hair loss due to alopecia areata.
It's treatable. Treatment often involves injecting steroids into the affected area, which blocks the inflammation. If the alopecia is more widespread, treatment may involve oral steroids or non-steroid immunosuppressant drugs.
It's closely related to other conditions. If you have one autoimmune disease, you're at greater risk for others. The pathways of your immune system are all interconnected and set off by inflammation.
It could go away and never come back. While a relapse is always possible, sometimes alopecia areata abates and never returns. It's a very unpredictable disease.