10 Warning Signs and Symptoms of Ankylosing Spondylitis You Should Know

Ankylosing spondylitis is a chronic inflammatory disease that primarily affects the spine and sacroiliac joints, causing pain, stiffness, and potentially leading to fusion of the vertebrae over time. This condition typically begins in early adulthood and can significantly impact quality of life if left undiagnosed or untreated. Understanding the symptoms is crucial for early detection and management.

Recognizing the warning signs of ankylosing spondylitis can be challenging, as symptoms often develop gradually and may be mistaken for common back pain. However, certain distinctive characteristics can help identify this condition. Below are the ten most important symptoms to watch for:

1. Chronic Lower Back Pain and Stiffness

The hallmark symptom of ankylosing spondylitis is persistent lower back pain and stiffness, particularly in the lumbar region and buttocks. This pain typically:

• Begins gradually, usually before age 40
• Lasts for at least three months
• Improves with exercise and movement
• Worsens with rest or inactivity
• Is often worse in the early morning or after periods of inactivity

Unlike mechanical back pain from injury or strain, inflammatory back pain from ankylosing spondylitis responds poorly to rest and actually feels better with physical activity. The stiffness can be so severe that it significantly limits mobility, especially upon waking.

2. Morning Stiffness Lasting More Than 30 Minutes

One of the most distinctive features of ankylosing spondylitis is pronounced morning stiffness that persists for at least 30 minutes, and often lasts for several hours. This stiffness:

• Affects primarily the spine and hips
• Gradually improves as the day progresses
• May require a hot shower or gentle stretching to alleviate
• Can make simple morning activities difficult

Patients often describe feeling like their back is “locked up” or “frozen” upon waking. This prolonged morning stiffness is a key differentiating factor from common mechanical back pain, which typically improves quickly after getting out of bed.

3. Pain in the Sacroiliac Joints

Sacroiliitis, or inflammation of the sacroiliac joints where the spine connects to the pelvis, is often one of the earliest manifestations of ankylosing spondylitis. This pain:

• Occurs in the lower back and buttocks
• May alternate from one side to the other
• Can radiate down one or both legs, mimicking sciatica
• Worsens when climbing stairs or transitioning from sitting to standing
• May be felt deep in the buttocks

The sacroiliac joint pain can be particularly troublesome at night and may cause difficulty sleeping. Many patients find it challenging to remain in one position for extended periods.

4. Reduced Flexibility and Range of Motion

As ankylosing spondylitis progresses, inflammation can lead to decreased spinal flexibility and limited range of motion. Patients may notice:

• Difficulty bending forward to touch toes
• Reduced ability to turn the head or look over the shoulder
• Stiffness when trying to twist the torso
• Progressive loss of normal spinal curves
• Inability to take deep breaths due to chest wall involvement

This reduced flexibility occurs because chronic inflammation can cause the vertebrae to gradually fuse together, a process called ankylosis. Early intervention and regular exercise are essential to maintain mobility and prevent severe limitations.

5. Chest Pain and Breathing Difficulties

Ankylosing spondylitis can affect the joints where the ribs attach to the spine, leading to chest-related symptoms:

• Pain in the chest wall and ribcage
• Difficulty taking deep breaths
• Reduced chest expansion
• Pain that worsens with coughing or sneezing
• Feeling of tightness around the chest

Inflammation of the costovertebral joints can make breathing uncomfortable and may limit lung capacity over time. This symptom is sometimes mistaken for heart or lung problems, making proper diagnosis essential. If chest expansion becomes severely limited, it may affect respiratory function.

6. Fatigue and General Malaise

Chronic fatigue is a common but often overlooked symptom of ankylosing spondylitis. This fatigue:

• Persists despite adequate rest
• May be severe enough to interfere with daily activities
• Often accompanies periods of increased inflammation
• Can affect concentration and mood
• May contribute to decreased quality of life

The ongoing inflammatory process in the body requires significant energy, leading to persistent tiredness. Additionally, disrupted sleep due to pain and stiffness contributes to daytime fatigue. Many patients report feeling exhausted even after a full night’s sleep.

7. Peripheral Joint Pain and Swelling

While ankylosing spondylitis primarily affects the spine, approximately 30-40% of patients also experience inflammation in peripheral joints:

• Shoulders, hips, and knees are most commonly affected
• Joints may become swollen, warm, and tender
• Ankles, wrists, and elbows can also be involved
• Symptoms may be asymmetric (affecting different joints on each side)
• Joint inflammation may come and go in flares

Hip involvement is particularly significant as it can severely limit mobility and may require surgical intervention in advanced cases. Shoulder pain can affect the ability to perform overhead activities and may restrict movement significantly.

8. Enthesitis (Inflammation Where Tendons Attach to Bone)

Enthesitis is inflammation at the sites where tendons and ligaments attach to bones, and it’s a characteristic feature of ankylosing spondylitis. Common sites include:

• Heel (Achilles tendon insertion)
• Bottom of the foot (plantar fascia)
• Around the pelvis
• Along the spine
• Ribcage

Patients with enthesitis often experience tenderness and pain when pressure is applied to these areas. Heel pain from Achilles tendinitis or plantar fasciitis may be particularly troublesome, making walking painful and affecting daily activities. This inflammation can occur before spinal symptoms develop, sometimes leading to delayed diagnosis.

9. Eye Inflammation (Uveitis or Iritis)

Approximately 25-40% of people with ankylosing spondylitis develop acute anterior uveitis, an inflammatory condition affecting the eye. Symptoms include:

• Eye pain and redness
• Sensitivity to light (photophobia)
• Blurred vision
• Increased tearing
• Usually affects one eye at a time

Uveitis requires prompt medical attention as untreated inflammation can lead to vision complications. Episodes typically come on suddenly and may recur. If you experience sudden eye pain or vision changes along with other symptoms of ankylosing spondylitis, seek immediate ophthalmologic evaluation.

10. Postural Changes

Over time, chronic inflammation and potential fusion of vertebrae can lead to characteristic postural abnormalities:

• Forward stooping or hunched posture
• Loss of normal lumbar curve (flattened lower back)
• Increased thoracic curve (rounded upper back or kyphosis)
• Forward head position
• Inability to stand fully upright

These postural changes develop gradually as the spine loses flexibility. The classic “question mark posture” occurs in advanced cases where the spine becomes fixed in a forward-bent position. Early diagnosis and consistent exercise therapy are crucial to prevent or minimize these structural changes. Maintaining good posture throughout daily activities and sleeping positions can help preserve spinal alignment.

Main Causes of Ankylosing Spondylitis

The exact cause of ankylosing spondylitis remains unknown, but research has identified several important factors that contribute to its development:

Genetic Factors

Genetics play a significant role in ankylosing spondylitis. The HLA-B27 gene is present in approximately 90% of people with this condition, though only about 5% of people with the HLA-B27 gene actually develop ankylosing spondylitis. Other genes have also been identified that may increase susceptibility. Having a family history of the condition significantly increases risk.

Immune System Dysfunction

Ankylosing spondylitis is classified as an autoimmune disease, where the immune system mistakenly attacks healthy tissues. In this case, the immune system targets the joints and entheses (where ligaments and tendons attach to bone), causing chronic inflammation. The reason why this immune system malfunction occurs is not fully understood.

Environmental Triggers

While genetics provide susceptibility, environmental factors may trigger the onset of disease in predisposed individuals. Potential triggers being studied include bacterial infections, particularly gastrointestinal infections, and changes in gut microbiome composition. However, no specific environmental cause has been definitively proven.

Sex and Age Factors

Ankylosing spondylitis most commonly begins in late adolescence or early adulthood, typically between ages 17 and 45. Men are diagnosed more frequently than women, though recent research suggests the condition may be underdiagnosed in women who often present with different symptom patterns.

Frequently Asked Questions

How is ankylosing spondylitis diagnosed?

Diagnosis involves a combination of medical history, physical examination, imaging studies (X-rays and MRI), and blood tests. The HLA-B27 genetic marker test can support diagnosis, though its presence alone is not definitive. MRI can detect early inflammatory changes before damage is visible on X-rays.

Can ankylosing spondylitis be cured?

Currently, there is no cure for ankylosing spondylitis. However, various treatments can effectively manage symptoms, reduce inflammation, and prevent or slow progression. Early diagnosis and consistent treatment are essential for the best outcomes.

Is ankylosing spondylitis hereditary?

Ankylosing spondylitis has a strong genetic component. If you have a first-degree relative with the condition, your risk is 10-20 times higher than the general population. However, having the genetic predisposition doesn’t guarantee you’ll develop the disease.

What’s the difference between ankylosing spondylitis and regular back pain?

Inflammatory back pain from ankylosing spondylitis typically begins before age 40, develops gradually, improves with exercise, worsens with rest, and causes significant morning stiffness lasting over 30 minutes. Mechanical back pain usually has a specific trigger, improves with rest, and worsens with activity.

Can exercise help with ankylosing spondylitis?

Yes, regular exercise is one of the most important aspects of managing ankylosing spondylitis. Physical therapy, stretching, and low-impact exercises help maintain flexibility, reduce stiffness, improve posture, and prevent spinal fusion. Swimming and yoga are particularly beneficial.

Does ankylosing spondylitis affect life expectancy?

Most people with ankylosing spondylitis have a normal or near-normal life expectancy, especially with proper management. However, the condition can increase risk of certain complications such as cardiovascular disease, osteoporosis, and spinal fractures, which is why regular medical monitoring is important.

At what age does ankylosing spondylitis typically start?

Symptoms typically begin in late adolescence or early adulthood, most commonly between ages 17 and 45. It’s rare for symptoms to first appear after age 45, though the condition may go undiagnosed for years, making the actual onset difficult to determine.

Can ankylosing spondylitis affect other parts of the body besides the spine?

Yes, ankylosing spondylitis can affect multiple body systems. Besides the spine, it can involve peripheral joints, eyes (uveitis), heart (rare), lungs (reduced chest expansion), and bowels (inflammatory bowel disease occurs in about 5-10% of cases). This is why comprehensive medical care is essential.

References:

• Mayo Clinic – Ankylosing Spondylitis
• Johns Hopkins Medicine – Ankylosing Spondylitis
• National Institute of Arthritis and Musculoskeletal and Skin Diseases
• Arthritis Foundation – Ankylosing Spondylitis
• NHS – Ankylosing Spondylitis