Ankylosing spondylitis (AS) is a rare type of inflammatory arthritis. It is characterized by inflammation, pain, and stiffness of the spine. Like other types of inflammatory arthritis, AS is known for periods of flare-ups (when symptoms worsen).

AS is a lifelong condition that generally starts in the lower back. As the disease progresses, it can affect the neck and damage other joints throughout the body. In severe cases of AS, the spine might become hunched.  

There is no cure for AS. Fortunately, plenty of medicines are available to ease pain and symptoms and slow down the effects of the disease. Exercise and physical therapy can help keep your back strong and reduce pain and stiffness.  

This article will cover symptoms of ankylosing spondylitis flare-ups, causes and triggers, length of flares, treatment, and more.

Types of Flare-Ups

Researchers have identified two types of flare-ups linked to AS: localized and generalized.

Localized flares cause symptoms in one primary area and lead to pain, fatigue, and mobility troubles. People with AS experience pain in several joints, flu-like symptoms, muscle spasms, and joint and muscle tenderness with generalized flares.  

Generalized flares are more severe and affect multiple body areas. In a 2021 study reported in the journal Rheumatology Advances in Practice, researchers found that 40% of study participants experienced generalized flares involving the entire body.

Symptoms of Ankylosing Spondylitis Flare-Ups

Symptoms of AS will vary from person to person and change the longer you have had the condition.  

Common flare symptoms include:  

• Low back, hip, and buttock pain: Pain may begin gradually, and depending on the severity of the flare, pain may worsen over days and weeks. You may feel discomfort on one side or both sides, and pain will spread over the affected areas. Pain might feel worse in the morning, at night while trying to sleep, during rest, and after inactivity. 
• Stiffness: You may experience stiffness in the low back, hips, and buttocks. A stiff back might make it harder to stand after sitting or lying down. Stiffness is also worse in the morning and night and may worsen with inactivity. 
• Neck pain and stiffness: During a flare, active inflammation in the joints and entheses (the connective tissues between tendons and ligaments and bone) of the neck can occur, especially in people who have had AS for many years.
• Pain in other joints: AS often focuses on the lower back, but it can also affect other joints. During a flare-up, you may experience inflammation in the joints of the pelvis, shoulders, spine, ribs, hips, and knees.
• Systemic symptoms: AS flare-ups can also cause whole-body symptoms, such as mild fever, sweating, weight loss, appetite loss, and mood changes.

What Triggers Flare-Ups?

Researchers do not know exactly what causes AS to flare up. In some instances, flare-ups follow an illness, infection, stressful situations, eating certain foods, not taking your AS medicines correctly, and overactivity.  

If you can learn what triggers your flares, you can take action to manage your flares by reducing stress, following a healthy and balanced diet, pacing yourself, and reaching out to your healthcare provider when you are not feeling well.

How Long Do Flare-Ups Last?

The duration and severity of AS flare-ups will vary person-to-person. For most people, flares are relatively short, lasting days to weeks.  

One study found that flare duration times have been going down because of advanced treatment options. The report’s authors also note people with non-radiographic AS (no joint damage seen on imaging) might have shorter flare durations than people with radiographic AS (joint damage seen on imaging).

Treatment Options

Treatment for an AS flare-up depends on the symptoms you are experiencing and their severity. Treatment might include:

• Over-the-counter (OTC) medications: OTC anti-inflammatory medicines like Advil (ibuprofen) can help reduce inflammation and pain.
• Corticosteroids: Your healthcare provider might prescribe a corticosteroid like prednisone for a severe flare to reduce inflammation and potentially shorten the flare’s length. It can be given as a pill or as an injection. An injection is sometimes given directly into a joint, e.g., the sacroiliac joint (where your lower back meets your pelvis), the hip, or the knee.
  
• Gentle exercise: Low-intensity exercise (walking, yoga, or swimming) can be helpful when you feel a flare coming on. Exercise in moderation and pay attention to your body’s signals. If you feel significant pain, weakness, or fatigue, these are signs to rest. Look for the balance between rest and exercise, even if all you can do is stretch while lying in bed.
  
• Hot and cold therapy: Both hot and cold therapy can help with swelling and pain relief. Try to alternate between heat and ice to encourage blood flow in the inflamed areas.
  
• Transcutaneous electronic nerve stimulation (TENS): A TENS machine uses electrical impulses to prevent nerves from sending pain signals to the brain, which can help reduce pain. Talk to your healthcare provider or a physical therapist about correctly using a TENS machine to manage AS pain.
  
• Stress management: Mind-body practices, such as meditation and deep breathing, can help you better cope with pain from an AS flare. These types of activities can promote relaxation and help to reduce anxiety and discomfort. 
  

How to Prevent Flare-Ups

You can prevent some flares by identifying triggers that lead to them—things like not taking AS medications, stress, or overactivity. Still, not all flares are preventable; sometimes, you may experience a flare without any triggers.

If you find you are experiencing AS flares frequently, you should talk to your healthcare provider to determine if your treatment plan is helping. Adjusting treatment doses, adding a new medicine, or switching out a treatment, could mean reduced frequency of flares.

Your healthcare provider might also suggest adjusting your AS medications during a flare to help reduce symptoms. You will want to write down new dosing requirements, how often to take the new dosing, and for how long.

Summary

It is common for people with ankylosing spondylitis to experience disease flare-ups. Flares can cause pain and stiffness of the spine and other joints. Some people might also experience severe fatigue and a depressed mood.   

There are many ways to manage AS flares, including OTC anti-inflammatory medicines, rest, gentle exercise, and TENS therapy. You can take steps to prevent flares from occurring by taking medication as prescribed and managing triggers like stress and overactivity. Reach out to your healthcare provider if you find you are experiencing frequent AS flare-ups.  

A Word From Verywell

Ankylosing spondylitis is a disease of progression, which means it will gradually worsen as you age. Fortunately, with appropriate treatment, it is rarely disabling or life-threatening. But symptoms like joint pain and fatigue still can interfere with your daily life.

AS treatments can reduce pain and other symptoms, reduce complications, prevent joint damage, and improve your quality of life. It is vital to see your healthcare provider regularly and follow your treatment plan exactly as they have prescribed. This is the best way to improve your outlook, stay active, and enjoy life.