Ankylosing spondylitis (AS) is a type of arthritis that primarily affects the spine, causing inflammation and pain. People with AS often experience periods of increased disease activity that they may refer to as flares.

AS can cause symptoms such as lower back, pelvis, and hip pain. These symptoms may appear or worsen during flares. When flares occur, a person may find relief by following the steps in their treatment plan.

It is not usually possible to prevent all flares, but a person can take steps to reduce their frequency and severity.

Doctors will often classify AS flares as either localized or generalized.

If a person is experiencing a localized flare, they will have symptoms that affect one area of the body. They may notice pain and immobility in the affected area, along with a general sense of fatigue.

Generalized flares are more severe than localized flares and affect more of the body. A person with a generalized AS flare may notice burning joints, muscle spasms, and flu-like symptoms, in addition to pain and immobility in the affected areas of the body.

Evidence suggests that AS flares are common. For instance, in a 2017 study, the participants reported experiencing, on average, at least one 2 week-long flare each month. An older study from 2010 involving 134 people with AS found that 70% of them experienced weekly flares.

The symptoms of AS flares can vary from person to person and among flares.

However, the symptoms that a person might experience as a result of AS flares include:

  • fever
  • fatigue
  • stiffness and pain in the back
  • joint pain, often in the rib cage, shoulders, hips, or knees
  • enthesitis, which is swelling and pain of the connective tissue
  • depression or anxiety

Other common symptoms can include:

  • rash
  • loss of appetite
  • weight loss
  • changes in vision or eye pain
  • trouble taking deep breaths
  • abdominal pain
  • loose stool

Managing AS flares often involves following an individual treatment plan. A person living with AS should work with a doctor to develop a treatment plan that helps them minimize flares and manage disease progression.

Common treatments for AS flares include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs): This type of medication, which includes ibuprofen and naproxen, can help reduce inflammation and pain. It is generally the first line of treatment.
  • Biologics: Doctors often use these medications, which target AS directly, when NSAIDs are not effective in managing symptoms and flares.
  • Gentle exercise: Low intensity forms of exercise, such as yoga, can help improve symptoms and prevent stiffness and pain in the spine and joints.
  • Massage therapy: Although this therapy may be effective in some cases, it might be best to avoid it during a flare.
  • Transcutaneous electrical nerve stimulation (TENS): TENS uses electrical impulses to prevent the nerves from signaling the brain, helping reduce pain.
  • Hot or cold therapies: Hot and cold therapies can help reduce swelling and provide some pain relief.

A person can take steps to help prevent AS flares from occurring. These include:

  • Managing stress: A person can try meditation, exercise, therapy, or other methods to help with stress.
  • Trying alternative pain relief methods: If medical treatments are not fully effective in relieving pain, a person may find that other methods, such as deep breathing or mindfulness, help them alleviate this symptom.
  • Exercising regularly: In particular, endurance and strength routines can help a person manage pain during a flare.
  • Taking a break when a flare is starting: A person may need to take a day off from school, work, or chores to help reduce the physical burden that may make a flare worse.

Often, a person cannot stop a flare from occurring, even if they use the methods above. It is important to follow a doctor’s recommendations for treating flares when they do occur.

Ankylosing spondylitis flare triggers

Experts do not fully understand the exact cause of AS. There is evidence to suggest that the HLA-B27 gene may increase the risk of AS, but not everyone with this gene will develop the condition.

Similarly, it is not clear what causes flares. However, a person may be able to identify certain factors that often lead to flares. For instance, illness, injuries, or emotional health may all have an influence.

Sometimes, flares might be due to treatment-related factors, such as a change in medication dosing, delayed dosing, or other adjustments to a person’s treatment plan.

Experts also suspect that stress may play a role in the occurrence of flares. Taking steps to reduce stress may help people reduce the frequency of their AS flares.

Flares may regularly occur in people living with ankylosing spondylitis. They can cause pain and stiffness in the spine and other joints, as well as symptoms in other areas of the body, such as the eyes. Some people with AS may also experience fatigue and depression.

Managing flares often involves following a treatment plan that a doctor has helped create. A person can take steps to help minimize the frequency and severity of flares, such as engaging in regular physical activity, managing stress, and avoiding known triggers.