The symptoms of ankylosing spondylitis may differ among individual sufferers. Usually the disease is progressive and slow in onset and development.

Sometimes the symptoms may take years to manifest and develop.

Age of onset

Symptoms usually start during later teenage years or during young adulthood. The symptoms vary in intensity over the years and may improve or get worse over many years.

It usually begins between ages 15 and 35 years (average 26 years). About 80% of patients develop the condition before they are 30 years of age and less than 5% present with the symptoms at an age above 45 years.

Men are around two to three times more likely to suffer from this condition. The initial symptom is typically a dull pain that is insidious or slow in onset.

Symptoms of ankylosing spondylitis

• Back pain and stiffness of the back – typically pain of the ankylosing spondylitis gets better with exercise and worsens on rest. A person often complains of a stiff and painful back early in the morning after a night’s rest. The pain and stiffness may last longer than 30 minutes after getting up and moving about in the morning. The pain may also worsen in the second half of the night after sleeping well the first half.
• Pain in the lower back and buttocks – there may be pain in the lower back and the buttocks if the lower part of the spinal column or the lumbar spine is affected. Commonly the sacroiliac joint of the hip joint is affected. This also causes pain in the lower back and the buttocks. 
• Inflammation, pain and swelling of the joints – apart from the spine, other joints may also be affected. Commonly hips, knees, wrists, shoulders and ankles may be affected. The main symptoms associated with arthritis include painful and restricted movement of the joint, swelling and warm joints are tender or painful on examination.
• Inflammation and pain at the site where the tendons or ligaments attach to bone (enthesitis) – tendons are tough cord like connections between the muscles and bones while a ligament is band of tissues that connect the bones to bones. Site of enthesitis include the top of the shin bone, the Achilles tendon or behind the heel, under the heel and the ends of the ribs. The ankle may be painful if the tendons and ligaments around the ankle is affected. If the ends of the ribs are affected, there is chest pain.
• Extreme fatigue and weakness
• If the eyes are affected with anterior uveitis there may be symptoms of pain in the eye, increased tears formation, redness, pain on light being shown in the eyes (photophobia) etc.
• Associated irritable bowel disease - around 60% of patients with ankylosing spondylitis also have IBD.