SYMPTOMS AND CAUSES OF ANKYLOSING SPONDYLITIS

Early symptoms of AS

The first symptoms of ankylosing spondylitis are usually pain and stiffness in the lower back and buttocks. However, sometimes, the pain may start in the neck rather than the back, especially in women.

Pain and stiffness may only be felt on one side or on alternate sides. Usually symptoms appear gradually, over a few weeks or months and can come and go (or “flare up”), eventually becoming persistent, chronic pain on both sides. It’s important to note that ankylosing spondylitis varies from person to person, and the onset of symptoms does, too.

Common AS symptoms

The pain AS causes lasts longer than 3 months, and you might notice the stiffness and pain are worse after you’ve been resting or sitting.

  • Pain feels worse when resting
  • Pain is alleviated when moving
  • Back feels stiff upon awakening

If any of these symptoms sound familiar, talk to your doctor. Over time, AS can start to worsen. It may even begin to restrict your spinal movement and, in more severe cases, cause fusing of the spine.

Other symptoms may include:

  • Fatigue The body uses energy to fight the inflammation of AS, and nighttime symptoms may affect sleep, which can contribute to fatigue.
  • Peripheral joint pain In a minority of individuals, pain does not start in the lower back, or even the neck, but in a peripheral joint such as the hip, ankle, elbow, knee, heel, or shoulder.
  • Loss of appetite In early stages of AS, individuals can experience loss of appetite.
  • Sacroiliac joint inflammation This is a common AS symptom. Sacroiliac joints are located at the base of the spine where it meets the pelvis.

Other areas where AS can affect you

AS often affects the area where connective tissues, such as ligaments and tendons, attach to bone. This area is called the enthesis. Enthesitis is inflammation in those areas. Click or tap on the hot spots to show where AS can affect you.

Person holding lower back showing inflammation in the lower spine
NECK

Women in particular may feel symptoms in the neck before the lower back

SHOULDER BLADES

Inflammation can progress to include the shoulders

RIBS

In severe cases, ribs can fuse together, making breathing more difficult

LOWER BACK

Frequent pain and stiffness in the lower back and buttocks are the most common early symptoms

HIPS

Over time, AS can include pain and stiffness in the hips

Causes of ankylosing spondylitis

While the exact causes of ankylosing spondylitis are not understood, it is known that genetics plays a role. A protein called HLA-B27 is produced by a gene that is found in many people with ankylosing spondylitis. However, you do not have to be HLA-B27 positive to have AS; nor do the majority of people with this genetic marker have AS.

Scientists believe that other causes of ankylosing spondylitis may include:

  • Other genes besides HLA-B27
  • A triggering environmental factor, such as a bacterial infection

Other signs and symptoms associated with AS

If you have any of the following problems in addition to back pain and stiffness, make sure to tell your doctor.

  • Family history of AS
  • History of uveitis or iritis (inflammation of the eye)
  • Frequent gastrointestinal issues that may be associated with Crohn’s disease or ulcerative colitis
  • Itchy, flaky skin rashes or history of psoriasis

This information could be helpful to your doctor when ruling out or diagnosing AS.

Diagnosing AS is important, as advanced symptoms may include hunched posture, “bamboo spine” (the appearance of a spinal column that resembles bamboo), and a fused spine (when the spine fuses together), which can happen as a result of chronic progressive disease and uncontrolled inflammation.

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