A lupus "flare" or "flare up" is when your lupus symptoms worsen and you feel ill as a result. The formal definition of a flare is: 

A measurable increase in disease activity in one or more organ systems involving new or worse clinical signs and symptoms and/or lab measurements. The increase must be considered clinically significant by the assessor (physician or clinical researcher) and in most cases, should prompt the consideration of a change or an increase in treatment.

Lupus is a chronic autoimmune disorder characterized by these unpredictable disease flares and remissions (when the symptoms improve and you feel better).

What does it mean when lupus is "active"?

When a lupus flare occurs, many people will notice a return of the symptoms they have experienced before. However, some people may also develop new symptoms. Active disease is caused by inflammation in an organ (such as the kidneys) or organ system (such as the digestive system). 

What happens in the body during a lupus flare?

Normally our immune systems, which is the part of the body that fights off viruses, bacteria, and germs (“foreign invaders,” like the flu), produce proteins called antibodies that protect the body from these invaders. Lupus is an autoimmune disease, meaning your immune system cannot tell the difference between these foreign invaders and your body’s healthy tissues and creates autoantibodies that attack and destroy healthy tissue ("auto" means "self"). These autoantibodies cause inflammation, pain, and damage in various parts of the body.

What are the symptoms of a lupus flare?

Common symptoms that indicate a flare are:

• Ongoing fever not due to an infection
• Painful, swollen joints
• An increase in fatigue
• Rashes
• Sores or ulcers in the mouth or nose
• General swelling in the legs

Some flares happen without symptoms. This is why it is important to see a trained lupus doctor who regularly monitors your health.

What can trigger a lupus flare?

Emotional stress -- such as a divorce, death in the family, or other life complications -- and anything that causes physical stress to the body -- such as surgery, physical harm, pregnancy, or giving birth -- are examples of triggers that can set off lupus or bring about a lupus flare. While a person’s genes may increase the chance that he or she will develop lupus, it takes some kind of external trigger to set off the illness or to bring on a flare. Other known triggers can include infections, colds or viral illnesses, exhaustion, severe exposure to ultraviolet rays, or an injury.

How can I tell the difference between normal fatigue and a lupus flare?

If you have lupus, and your work or home life requires high levels of energy, it is normal to feel exhausted. Not every bout of fatigue is a lupus flare. You might feel you are having a flare when your symptoms are new or worse or you feel sick. But your doctor will also need to make sure that your symptoms are due to lupus activity and not some other cause, such as medication side effects or an infection.

The best way to determine whether or not you are having a flare is to take some time to understand what your triggers are and how to avoid them whenever possible. Make a plan for flares and share it with your doctor. Your plan can be a great tool to advocate for your needs — and make sure you and your doctor are communicating well.

Finding a healthcare professional experienced in lupus you feel comfortable talking to and have access to is important in understanding these differences. Look for a care team that listens to your questions and makes you feel respected and heard. And don’t be afraid to ask questions again, take notes, or bring someone you trust to your appointments. Having the right support system in place is a key way to manage your lupus — so you can focus on living your life.

Your Lupus Flare Plan

Download a worksheet that is designed for you to fill in with help from the doctor who's managing your lupus care and treatment. Keep the completed worksheet to use as a guide when you have a lupus flare.

Download the Flare Plan Template (PDF)

History

Until recently there was no community-wide agreement on how to define clinical flares in lupus patients. Various clinical trials have used different definitions of flare, making it hard to compare results or interpret outcomes.

In 2005, the U.S. Food and Drug Administration (FDA) identified the need for a consistent definition of a lupus flare to enable more precise outcome measures for research studies, such as the number of flares or the time between flares.

The Lupus Foundation of America responded by spearheading a four-year, worldwide initiative to develop the very first universally accepted definition of a lupus flare. Published in 2010, this consensus definition of a lupus flare facilitates new drug development and helps physicians characterize lupus with standard, agreed-upon language.