Signs and Symptoms of Ankylosing Spondylitis

A checklist of ankylosing spondylitis (AS) symptoms can include early signs like pain and stiffness in the lower back, especially after periods of rest or inactivity. People with AS may also experience fatigue, neck pain, and unintentional weight loss.

AS is a type of inflammatory arthritis that affects the joints and ligaments in the spine. No two people experience AS the same way, but symptoms develop gradually over time and tend to come and go. Many people with AS experience flares (periods of worsened symptoms) and remission (periods of little to no symptoms). You may experience cycles of flares and remission throughout your life.

Lower Back Pain and Stiffness 

Pain and stiffness in the lower back are the most common symptoms of AS. These symptoms occur when inflammation affects the sacroiliac joints, which are located between the pelvic bone and the base of the spine.

AS pain and stiffness typically come on gradually and may feel like a "dull" pain on one side of the back at first. You might notice stiffness or pain at night or after long periods of activity, which may cause discomfort while you sleep. Light physical activity (e.g., stretching or yoga) or taking a warm bath after you wake up usually helps relieve back aches in the morning.

Joint Pain 

The inflammation that AS causes can spread to other joints, leading to pain in the hips, shoulders, ankles, knees, and elbows. About 15% of people with AS also experience jaw pain.

The severity of joint pain varies from person to person. Joint pain might occur during flares or become more persistent as your condition progresses. The joint pain between the spine and ribs can worsen as the disease progresses, sometimes making it challenging to take a deep breath.

Enthesitis

Enthesitis is inflammation of the entheses, or areas where your tendons or ligaments attach to your bone. This symptom is common and can cause pain and tenderness in many areas of the body.

Most people with AS feel tenderness in the heel of one or both feet, which can make walking painful. Inflammation can cause bone loss or lead to abnormal bone growth over time. This may result in painful bone spurs, or small bumps of extra bone that attach to existing bones. 

Fatigue 

Nearly 90% of people with AS experience fatigue, which can significantly affect daily functioning and quality of life. Several factors may contribute to fatigue, such as:

• Chronic pain can make it difficult to sleep, contributing to fatigue and grogginess.
• Inflammation may force your body to expend too much energy trying to repair damaged tissues.
• The psychological impact of living with a progressive condition like AS can lower your energy levels and interfere with your ability to get a good night's sleep.

Anterior Uveitis 

Anterior uveitis, also known as iritis, is inflammation that affects the middle layer of the eye, specifically the colored ring around the pupil (iris). Symptoms of anterior uveitis include eye pain, redness, light sensitivity, and blurry vision. These symptoms may suddenly appear and can be severe.

It's a good idea to see an eye care specialist (e.g., an optometrist or ophthalmologist) sooner rather than later if you notice these symptoms. Anterior uveitis can lead to serious complications—such as glaucoma, cataracts, or vision loss—if untreated.

Limited Mobility 

Inflammation can cause the spine and other joints to become stiff and rigid, leading to a loss of flexibility and mobility. The spinal vertebrae may become fused together in severe cases, causing a hunched-over posture. This can make bending, twisting, or rotating the body difficult.

Limited mobility caused by AS can significantly affect daily living. You might have challenges with everyday activities, such as getting dressed, bathing, and cooking. Losing your range of mobility might also make it difficult for you to work or participate in leisure activities. 

Other Symptoms 

AS-related inflammation can affect more than just the spine. Other body systems can be affected, leading to other symptoms like:

• Chest pain
• Difficulty breathing
• Irregular heartbeat 
• Loss of appetite and unintentional weight loss 
• Skin rash
• Stomach or digestive problems 

Flare Symptoms 

Every person from AS experiences flares differently. Flares can range from mild to severe, last a few days to several weeks, and may be localized or generalized. Localized flares affect only a specific body part, such as a single joint or the lower back. Generalized flares cause more widespread symptoms in several body parts.

Symptoms may include:

• Fatigue
• Increased pain and stiffness in the lower back and neck
• Lack of appetite and weight loss
• Mild fever
• Mood changes
• Tenderness in other joints (e.g., shoulders, hips, ribs, knees)

Symptoms in Children 

Most people with AS receive their diagnosis during adulthood, but some children and adolescents can also develop the condition. Between 10% to 20% of adults with AS first experienced their symptoms during childhood. This condition is called juvenile ankylosing spondylitis (JAS). 

JAS is two to three times more common in males than females. Common symptoms include:

• Back pain and stiffness that occurs at night or early in the morning 
• Fatigue
• Mild fever
• Shortness of breath
• Stooped posture
• Swelling in the ankles, heels, buttocks, toes, knees, ribs, upper back, shoulders, and neck 
  

Symptoms in Women 

Back pain is a key characteristic of AS in both women and men, but symptoms can look different in women. This can sometimes lead to a delayed or incorrect medical diagnosis in women.

Research has shown that women with AS have:

• Intense fatigue 
• Longer duration of morning stiffness 
• Loss of flexibility in the spine and other joints 
• More pain in the neck, knees and hips
• Significantly higher rates of night pain and sleep disturbances or discomfort 

Men and women often experience different AS-related complications. Women are more likely to have inflammatory bowel disease (IBD) and psoriasis. Men are more likely to experience anterior uveitis.

When To Contact a Healthcare Provider 

You may want to visit a healthcare provider if you notice AS symptoms, particularly morning back pain and stiffness, which get better with physical activity. Make sure you mention any other symptoms you have, such as fatigue or joint pain. 

The healthcare provider provider will likely perform a physical exam and order blood tests or imaging studies to learn more about your symptoms. They may refer you to a rheumatologist (who specializes in the joints, muscles, and bones) to confirm an AS diagnosis. 

A Quick Review 

AS is a type of inflammatory arthritis that affects the joints and ligaments of the spine. The hallmark symptom of AS is pain and stiffness in the lower back and hips. Inflammation can also cause fatigue and joint pain in other parts of the body, including the neck, shoulders, and ankles. AS is a lifelong condition, but treatment can help manage symptoms and slow disease progression.