Ankylosing Spondylitis – Symptoms and Causes

ByJanis Updated

Overview

Spine fusion disease is a type of inflammatory condition that affects the spine over time. The disease causes vertebrae (the bones in your spine) to slowly fuse together.

When this happens, your spine becomes less flexible, and you might develop a hunched posture. If the inflammation reaches your ribs, you may find it difficult to breathe deeply.

As the disease progresses, your body tries to heal by forming new bone. This new bone gradually creates bridges between vertebrae until they fuse together.

This fusion often flattens the natural curves of your spine, leading to stiffness and a fixed, hunched position.

Doctors recognize two types of this condition. When visible on X-rays, it’s called spinal fusion. When not visible on X-rays but diagnosed through symptoms, blood tests, and other imaging, it’s known as nonradiographic axial spondyloarthritis.

Most people start showing symptoms in early adulthood. The inflammation can also affect other body parts, especially the eyes.

While there’s no cure, treatments can help reduce symptoms and may slow down the disease’s progression.

Treatment Options

  • Medication therapy to reduce inflammation
  • Physical therapy to maintain flexibility and posture
  • Exercise programs designed for spine health
  • Pain management techniques
  • Breathing exercises when chest mobility is affected
  • In severe cases, surgical interventions

Symptoms

Ankylosing spondylitis often begins with back pain and stiffness in the lower back and hips. These symptoms are typically worse in the morning or after sitting still for a while. Many people also feel tired and may have neck pain.

The main areas affected by ankylosing spondylitis include:

  • The joint connecting the spine to the pelvis
  • Lower back vertebrae
  • Areas where tendons and ligaments connect to bones (especially in the spine and sometimes in the heel)
  • The cartilage between the breastbone and ribs
  • Hip and shoulder joints

Symptoms may come and go over time. Some people experience periods when their symptoms get worse, followed by times when symptoms improve or disappear completely. This pattern varies from person to person and is often unpredictable.

When to Visit a Healthcare Provider

You should get medical help if you have pain in your lower back or buttocks that:

  • Started gradually
  • Feels worse in the morning
  • Wakes you up at night (especially after midnight)
  • Gets better with physical activity
  • Gets worse when resting

Urgent eye care is needed if you experience:

  • Painful red eye
  • Cannot tolerate light
  • Blurry vision

These symptoms should not be ignored as they may indicate a condition requiring proper diagnosis and treatment.

Causes

Scientists haven’t found the exact cause of ankylosing spondylitis yet. Research shows genetics plays an important role in who develops this condition.

People with the HLA-B27 gene face a much higher risk of getting ankylosing spondylitis than those without it.

However, having this gene doesn’t guarantee someone will develop the disease. Many people carry the HLA-B27 gene but never experience any symptoms or problems related to ankylosing spondylitis.

Risk Factors

Ankylosing spondylitis typically starts in the late teens or early twenties. The HLA-B27 gene is present in most people with this condition.

However, having this gene doesn’t guarantee you’ll develop the disease. Many people carry the HLA-B27 gene but remain healthy without any symptoms.

Problems That May Develop

In severe cases, the body tries to heal by forming new bone. This new bone slowly connects the spaces between vertebrae, eventually causing parts of the spine to fuse together. These fused sections become rigid and unable to move normally.

When the rib cage stiffens, breathing can become more difficult as lung function decreases.

Several other serious issues may arise:

  • Eye inflammation (Uveitis): A common problem that causes sudden eye pain, light sensitivity, and blurry vision. Seek medical help immediately if these symptoms appear.

  • Broken bones – Bones may weaken during early disease stages. Weakened vertebrae can collapse, making stooped posture worse. These fractures might put pressure on the spinal cord and nerves, potentially causing injury.

  • Heart complications – The condition can affect the aorta (the body’s largest artery). Inflammation can cause the aorta to enlarge, changing the shape of the heart’s aortic valve and affecting how it works.

Health Writer

Janis's areas of expertise include nutrition, exercise, stress management, and mental health. She is passionate about educating and empowering people to take control of their health and make positive changes that can last a lifetime. Janis believes that small, sustainable changes are the key to long-term success, and she works with her clients to develop personalized plans that fit their individual needs and lifestyles.