Ankylosing spondylitis (AS) is a chronic inflammatory disease that primarily affects the joints of the spine, leading to pain, stiffness, and eventually, fusion of the vertebrae. AS is a type of spondyloarthritis, which is a group of rheumatic diseases that primarily involve inflammation of the spine and large joints.

Overview:

Further, ankylosing spondylitis is characterized by inflammation of the spinal joints especially the sacroiliac joints where the spine meets pelvis. With time, chronic inflammation can cause new bone formation leading to fusion of the vertebrae. AS typically starts in early adulthood and progresses slowly over time. Furthermore, AS also involves other articular structures like tendons and ligaments of joints as well as heart, lung and eyes sometimes.

Symptoms:

Symptoms vary from person to person and may include:

1. Chronic Back Pain: Continuous pain or stiffness in lower back that gets worse with resting while getting better with activity.
2. Stiffness: Stiffness and limited range of motion (ROM), particularly in the morning or after periods of sitting or lying down.
3. Pain and Swelling: Painful, swollen hips or knees or shoulders or any other joint(s).
4. Fatigue: Overall fatigue and a feeling of poor health during active disease phases.
5. Loss of Flexibility: Slow loss of flexibility which results in inability to stand erect.
6. Eye Inflammation: Eyes inflamed (uveitis/iritis) with redness, pain, photophobia (light sensitivity) among others.
7. Difficulty Breathing: Difficulties breathing can also be seen arising out of limitations on lung function due to fusion between ribs and vertebrae (rarely).

Causes:

The exact cause of ankylosing spondylitis remains unknown; however, it is believed to be the result of environmental factors combined with genetics. In fact, the strongest genetic link is associated with HLA-B27 gene while some people having this condition do not possess HLA-B27 gene at all. On the other hand, infections or peculiar lifestyles might provoke or worsen inflammation in people who have a genetic susceptibility toward this disease process.

Diagnosis:

To determine if a patient has ankylosing spondylitis, the doctor will use a combination of clinical evaluation, medical history, imaging studies and laboratory tests for diagnosis. The main criteria for diagnosis include:

1. Symptoms: Chronic back pain (spinal cord pain) and stiffness lasting over three months usually improves with exercise and becomes worse with rest.
2. Physical Examination: Inspection of spinal movements, joint swellings and other signs of AS.
3. Imaging Studies: X-rays or magnetic resonance imaging (MRI) may show typical changes in the sacroiliac joints as well as spine comprising erosion, sclerosis and new bone formation respectively.
4. Laboratory Tests: Blood tests may indicate inflammation by showing increased levels of C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR), though these measures are not specific to AS.

Treatment:

The treatment of ankylosing spondylitis is aimed at alleviating symptoms, minimizing inflammation and preventing complications. Some options may include:

1. Medicines: Non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation, disease modifying anti rheumatic drugs (DMARDs) that control the immune system, and biotherapeutics such as Tumor necrosis factors (TNF) inhibitors which target certain inflammatory pathways.
2. Physical therapy: Exercise programs and physical therapy can help improve flexibility, posture and strength as well as maintain the mobility of the spine.
3. Lifestyle changes: This includes ways to relieve or manage symptoms and promote overall wellness like regular exercising, proper body posturing while sitting or standing with good back support, avoiding smoking.
4. Surgery: In severe cases of AS where there is extensive spinal fusion and deformity, corrective surgery may be performed in order to bring the spine into alignment thereby removing pressure on nerves leading to more movement within the area being treated.

Prognosis:

The prognosis for patients with ankylosing spondylitis depends on how serious the symptoms are; how they respond to treatment; if there are any other illnesses present besides this one; Despite it being incurable but a chronic condition, once diagnosed early with appropriate management it helps in controlling symptoms hence may slow down progression of the disease enabling better life quality. Regular monitoring by doctors or healthcare providers and adherence to treatment recommendations are essential for controlling outcomes and decreasing long-term complications.