What is ankylosing spondylitis?

Ankylosing spondylitis is a type of arthritis that causes inflammation in certain parts of the spine. It may also affect the knees, ankles, and hips. This inflammation in the joints and tissues of the spine can cause stiffness. In severe cases, this may cause the bones in the spine to grow together, which can lead to a rigid spine that is difficult to bend.

Many people with ankylosing spondylitis have mild episodes of back pain and stiffness that come and go. But others have severe, ongoing back pain and stiffness. Some people with ankylosing spondylitis develop:

  • Eye disease.
  • Skin disease (psoriasis).
  • Gut disease.

Who gets ankylosing spondylitis?

Anyone can get ankylosing spondylitis; however, certain factors may increase your risk for developing the disease, such as:

  • Family history and genetics. If you have a family history of ankylosing spondylitis, you are more likely to develop the disease.
  • Age. Most people develop symptoms of ankylosing spondylitis before age 45.
  • Other conditions. People who have Crohn’s disease, ulcerative colitis, or psoriasis may be more likely to develop the disease.

What are the symptoms of ankylosing spondylitis?

The most common symptom of ankylosing spondylitis is lower back and/or hip pain and stiffness. Over time, the symptoms may move to other areas of the spine. The pain typically gets worse during periods of rest or inactivity, such as in the middle of the night or after sitting for a long time. Usually, moving and exercise can help pain get better. 

Some people with ankylosing spondylitis have mild episodes of pain that come and go, while others will have long-lasting, severe pain. If you have ankylosing spondylitis, whether mild or severe, you may have times when the symptoms get worse (flares) and other times when the symptoms improve (remission). 

The disease can affect other areas of the body. Other symptoms may include:

  • Pain, stiffness, and inflammation in other joints.
  • Difficulty taking deep breaths if the joints connecting the ribs are affected.
  • Vision changes and eye pain.
  • Feeling very tired.
  • Loss of appetite and weight loss.
  • Skin rashes.
  • Abdominal pain and loose bowel movements.

What causes ankylosing spondylitis?

No one knows the cause of ankylosing spondylitis. Studies show, however, that both genes and things in our environment may lead to the development of the disease.

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