Selena Gomez has already had a long, hard battle with lupus. But this week, the 24-year-old announced she would be taking time off to deal with the illness — and anxiety associated with it.Although lupus is relatively rare (affecting 1.5 million Americans), the vast majority of lupus patients are women. It is more common among Black and hispanic women than white women. Here's what you need to know about the condition.It's a chronic autoimmune condition that occurs when your body's immune system attacks parts of your body. This causes inflammation that can affect a bunch of different organs and tissues , including your heart, kidneys, skin, and joints.Many symptoms of lupus — including headaches, fatigue, joint pain, and, shortness of breath — are similar to those found in other conditions. That can make accurately diagnosing lupus a challenge.The most distinctive symptom of lupus is a rash on the face. It's often described as being "butterfly-shaped" and covers your cheeks and the bridge of your nose. However, not everyone with lupus gets this rash. In fact, each individual case of lupus comes with its own specific combination and severity of symptoms. One person may experience joint pain and fatigue, while other cases of lupus can involve serious inflammation in important organs, such as the kidneys. Complicating things further is the fact that symptoms may come and go (in what's known as "flares"), and they can change over time.In most cases, what triggers lupus remains a mystery. But researchers believe that genetics and environmental factors (including sun exposure, previous infections, and medications) all play a role. For instance, someone who has a genetic predisposition for lupus may be triggered to develop the condition after taking certain types of medication.Although lupus doesn't have a direct effect on mental health, like many chronic illnesses, it can definitely exacerbate symptoms of issues that are already present. People with depression and anxiety often report new episodes or more severe symptoms when another condition, such as lupus , is present — because the physical and emotional demands of dealing with a chronic disease can cause a lot of added stress.Because lupus is a condition of the immune system that affects so many processes in your body, the illness can come with a lot of serious complications. People with lupus are more vulnerable to all kinds of other conditions, including everything from common infections to cancer and issues with pregnancy (including miscarriage). Treatment for lupus usually focuses on treating these associated issues.That means your doctor might give you medication to ease pain, prevent viral infections, correct hormonal imbalances, or suppress your immune system during a flare-up. Most people with lupus do find a treatment plan that helps them avoid flare-ups of their symptoms. But because it can change over time, treating the disease requires lifelong management.Because these complications can be serious, it's important that you work with your doctor to get an accurate diagnosis if you think you might have lupus. It also often requires listening to your body and caring for yourself when needed, as Gomez is doing now.