The exact cause of AS is unknown, though genetics play a major role. Men are three times more likely to be affected than women, with symptoms typically appearing in the late teens or early 20s.

Ankylosing Spondylitis (AS) is a systemic condition, meaning it affects more than just the back. Symptoms typically manifest as inflammation in the spine, joints, and even vital organs.

1. Early Warning Signs & Spinal Symptoms

The hallmark of AS is inflammatory back pain. Unlike mechanical back pain, AS symptoms often follow a specific pattern:

• Gradual Onset: Pain and stiffness develop slowly over months rather than appearing suddenly.

• Morning Stiffness: Discomfort is most severe in the morning or after long periods of rest.

• Relief Through Movement: Symptoms typically improve with physical activity, heat, or a warm shower.

• Systemic Fatigue: Constant tiredness is a frequent side effect of the body's active inflammatory response.

• Flu-like Symptoms: Early stages may include a mild fever, loss of appetite, and general malaise.

2. Progressive Spinal Fusion (Ankylosis)

Chronic, untreated inflammation can lead to bony fusion, where the vertebrae grow together.

• Loss of Mobility: Once the spine fuses, the pain may subside, but the spine becomes rigid and inflexible.

• Increased Fracture Risk: A fused spine is brittle. Even minor trauma (like a fall or car accident) can cause serious fractures, most commonly in the cervical spine (neck).

• Physical Changes: Advanced AS often causes a forward curvature of the upper back (Thoracic Kyphosis), which can significantly restrict breathing.

3. Peripheral Joint Involvement

While AS is known for spinal impact, it frequently affects other joints—a trend seen more often in women.

• Large Joints: Swelling, redness, and heat in the hips, knees, and ankles.

• Dactylitis: Small joints in the toes may become so inflamed they appear "sausage-shaped."

• Enthesitis: Inflammation where tendons meet bone. Common examples include Achilles tendinitis (heel pain) and Plantar Fasciitis (pain on the bottom of the foot).

• Costochondritis: Inflammation of the cartilage around the breastbone, making deep breaths painful.

4. Systemic Complications (Eyes, Heart, and Kidneys)

Because AS is a systemic disease, it can trigger complications in other organ systems:

• Ocular Health (Iritis & Uveitis): Inflammation of the eye’s iris or uvea causes redness, pain, and sensitivity to light. Note: This requires urgent care from an ophthalmologist to prevent permanent vision loss.

• Cardiovascular Issues: Rarely, inflammation can scar the heart’s electrical system, leading to a slow heart rate (Heart Block) or causing the Aorta to leak, which can lead to heart failure and dizziness.

• Renal Health (Kidney Failure): Advanced cases can lead to Amyloidosis, a buildup of proteins in the kidneys. This may eventually result in kidney failure, requiring dialysis.

There is no single "gold standard" test, but doctors typically use a combination of:

1. Physical Examination: Testing the range of motion in the spine and chest expansion.

2. Imaging (X-ray & MRI): Detecting sacroiliitis (inflammation of the SI joints) or early bone changes.

3. Blood Tests: Checking for the HLA-B27 marker and inflammatory markers like CRP (C-reactive protein) and ESR.