The most common symptom of ankylosing spondylitis is lower back pain. Similar to rheumatoid arthritis, the pain associated with ankylosing spondylitis is dull and aching at first. Many people will also experience pain in the legs, shoulders, buttocks and the back of their knees. The ankle may be very tender in the spot where the tendon attaches to the bone. This is called enthesopathy.
Other common symptoms of ankylosing spondylitis include:
- gradual onset of lower back pain and stiffness over a period of weeks or months
- duration of symptoms longer than 3 months
- early morning stiffness which is improved by a warm shower or light exercise
- fatigue, weight loss and low-grade fever
- difficulty in sleeping or disturbed sleep patterns
Unlike a back injury, such as a ruptured disc, ankylosing spondylitis will usually get worse with rest and better with movement. There is also a loss of motion in the lower spine by the flattening in the curve of the back. A long-term worry with ankylosing spondylitis is that the joints connecting the vertebra will merge together leaving a person permanently hunched over. An exercise program may help prevent this from happening.
Other parts of the body may also be affected. Often, a person with ankylosing spondylitis will have an inflammation of the eye called iritis. This condition is easily treated by an eye doctor and will leave no permanent injury.
Ankylosing spondylitis can also occur in the upper part of the body, but this is less likely. If the chest is involved, there may be interference with a person’s ability to breathe along with diminished chest expansion. Lungs may also be affected because of scar tissue from the inflammation. Rarely, the heart valves of the aorta can be injured because of the inflammation caused by ankylosing spondylitis. Surgery may be necessary to correct this problem.
Ankylosing spondylitis is usually active for about ten years and may then level off. But, it can leave permanent damage to your spine, hips or knees. People who acquired ankylosing spondylitis as a teenager are more likely to have other types of arthritis and need a hip replacement than those who developed ankylosing spondylitis after age 30.
Ankylosing spondylitis can be difficult to diagnose because the symptoms are similar to other diseases, such as rheumatoid arthritis. To make a correct diagnosis, your doctor will ask you for your medical history, conduct a physical examination and order x-rays to be taken of the joints to see if there are any tissue changes. Sometimes, tissue changes will not appear on x-rays in the earlier stages of ankylosing spondylitis. Your doctor will then rely on your symptoms and physical examination to make a diagnosis. He or she may also want to find out if you have the HLA-B27 gene.