Knowing when you might have a flare-up and what to expect can help you manage your AS. Once you recognize the symptoms of a flare-up, you can take steps to ease them and avoid triggers.

Ankylosing spondylitis (AS) is a type of autoimmune arthritis that typically affects the joints in your spine, hips, and lower back. This condition causes inflammation, which can lead to pain, swelling, stiffness, and other symptoms.

Like other kinds of arthritis, AS can sometimes flare. A flare-up happens when symptoms worsen. During a flare-up, you might need more care and treatment than you need at other times. Remission or partial remission is when you have fewer, milder, or no symptoms.

You can talk with your doctor about the best ways to help prevent and soothe your symptoms. There are several ways to ease symptoms and treat AS.

Flare-ups and their symptoms can differ for every person with AS.

Most people with this condition start to notice symptoms at ages 17–45. Symptoms can also begin during childhood or older adulthood. AS is 2.5 times more common in men than in women.

There are two main kinds of AS flare-ups:

  • Local: in one or two areas only
  • General: throughout your body

Symptoms of AS flare-ups may change depending on how long you’ve had the condition.

Pain in your lower back, hips, and buttocks

Pain may begin gradually over a few weeks or months. You may feel discomfort on only one side or on alternating sides. The pain normally feels dull, not sharp, and spreads over the area.

The pain is usually worse in the mornings and at night. Resting or being inactive may worsen the pain.


You may have stiffness in your lower back, hips, and buttocks area. Your back may feel stiff, and it might be slightly difficult to stand up after sitting or lying down. Stiffness is typically worse in the morning and at night and improves during the day. It may get worse during rest or inactivity.

Neck pain and stiffness

The Spondylitis Association of America notes that women may be more likely to have symptoms that start in the neck instead of the lower back.


Inflammation and pain can lead to fatigue and tiredness. Your fatigue may worsen if you experience disturbed sleep at night due to pain and discomfort. Reducing inflammation can help manage fatigue.

Other symptoms

Inflammation, pain, and discomfort can cause loss of appetite, weight loss, and a mild fever during flare-ups. Managing pain and inflammation can help ease these symptoms.

Long-term AS flare-ups typically cause signs and symptoms in more than one part of your body.

Chronic back pain

An AS flare-up may cause chronic back pain over time. You may feel dull to burning pain on both sides of your lower back, buttocks, and hips. Chronic pain can last for 3 months or longer.

Pain in other areas

Pain can spread to other joints over a few months or years. You may have pain and tenderness in your middle to upper back, neck, shoulder blades, ribs, thighs, and heels.


You may also have more stiffness in your body over time. Stiffness may spread to your upper back, neck, shoulders, and rib cage. It may be worse in the mornings and get only slightly better during the day. You may also have muscle spasms.

Loss of flexibility

You may lose flexibility in some of your joints, including those in your back and hips. Long-term inflammation in and around your joints can fuse or join bones together. This makes your joints stiff, painful, and hard to move.

Difficulty breathing

Bones in your rib cage can also fuse or join together. Your rib cage is designed to be flexible to help you breathe. If your rib joints become stiffer, it may be harder for your chest and lungs to expand. This may make your chest feel tight.

Difficulty moving

AS can affect even more joints over time. You may have pain and swelling in your hips, knees, ankles, heels, and toes. This can make it difficult to stand, sit, and walk.

Stiff fingers

AS flare-ups may spread to your fingers over time. This can make your finger joints stiff, swollen, and painful. You may have difficulty moving your fingers, typing, and holding or opening things.

Eye inflammation

AS is a risk factor for eye inflammation, a condition called iritis or uveitis. This condition causes redness, pain, blurry vision, and floaters in one or both eyes. Your eyes may also be sensitive to bright light.

Lung and heart inflammation

In rare cases, AS flare-ups may affect your heart and lungs over time.

AS is known to be caused by certain infectious organisms, stress, and traumatic injuries. These factors can also trigger a flare-up, along with fatigue, mood changes, and lack of sleep.

It’s not always possible to prevent or regulate flare-ups. Some people with AS may feel that their flare-ups have certain triggers. Knowing your triggers, if you have any, may help you prevent flare-ups.

In a 2002 study that included 214 people with AS, 80% of participants said they felt that stress triggered their flare-ups.

The duration and frequency of flare-ups vary among people with AS.

In one 2010 study, researchers followed 134 people with AS for 3 months. Seventy percent of the participants reported a flare-up in any given week, though only 12% reported a major generalized flare in any given week.

Flare-ups may last from a few days to 3 months or longer.

Treatment will depend on what type of symptoms you experience and how severe they are. Here are some possible treatments to help during flare-ups:

  • light exercise and stretching
  • a warm shower or bath
  • heat therapy, such as a warm compress
  • nonsteroidal anti-inflammatory drugs such as aspirin, ibuprofen, or naproxen
  • an anti-inflammatory diet
  • physical therapy
  • prescription medications
  • massage therapy
  • steroid injections
  • a hand or wrist brace
  • a knee or foot brace
  • steroid eye drops
  • eye drops to dilate your pupils

Healthy lifestyle habits may also help you manage flares. For example, regular exercise and physical therapy may help reduce pain and stiffness.

If you smoke, it may be beneficial to try to quit. People with AS who smoke are at higher risk of spine damage. AS can also affect your heart, and you may have a higher risk of heart disease and stroke if you smoke. It’s a good idea to avoid secondhand smoke as well.

Take all medications exactly as prescribed to help prevent and soothe flare-ups. Your doctor may prescribe one or more medications that help manage inflammation. This may help prevent or ease flare-ups. Drugs used to treat AS include:

Any disorder or condition can lead to emotional symptoms. You can talk with your doctor about your emotions or seek the help of a mental health professional.

Getting involved with a support group can help you feel more in control of your treatment. Talking with other people who have AS can help you find the best way to manage the condition for yourself. You can also join an AS organization to stay up to date on health research.

Your experience with AS flare-ups will not be the same as someone else’s experience with this condition. Pay attention to your body. You may find it helpful to keep a daily journal of your symptoms, your treatments, and any possible triggers you notice.

Tell your doctor if you think a treatment is helping to prevent flares or reduce symptoms or if you feel that a certain treatment isn’t helping you. Something that worked for you before may no longer work over time. Your doctor may need to change your treatments as your AS changes.