Just as exercise can keep your spine flexible, deep-breathing exercises can keep your chest wall elastic and preserve your ability to take a deep, cleansing breath — important because, without these preventive steps, ankylosing spondylitis can make deep breathing difficult or even impossible.

In normal breathing, the ribs move up and down every time you breathe. In ankylosing spondylitis, the rib joints that attach to the spine can stiffen or even fuse because of inflammation. As a result, the ribs can lose their ability to rise and fall. This chest wall tightening, which some describe as a feeling of being strapped in, leaves people feeling short of breath, even after mild activities. If the ribs fuse, you will still be able to breathe — the major muscle used in breathing, the diaphragm, isn't affected — but not deeply.

Up to a third of people with ankylosing spondylitis have reduced chest wall expansion, said John Reveille, MD, director of the division of rheumatology and clinical immunogenetics at the University of Texas Health Science Center at Houston Medical School. "Since we routinely measure chest expansion in our AS patients, it's surprising to see how many of them have no chest expansion whatsoever," he added. This usually happens later in the course of the disease. "As a rule, by the time you are seeing zero chest expansion, you tend to see a fused spine," he said.

In addition, costochondritis can cause chest pain with ankylosing spondylitis. This is inflammation of the cartilage that attaches the ribs to the breastbone, and those with AS are more susceptible to it. When you go to take a deep breath, it's very painful, Dr. Reveille said.

Deep Breathing: Ankylosing Spondylitis Essential

Deep-breathing exercises "can help maintain your ability to move your ribs at the breastbone and at the thoracic (middle) spine," said Olivia Ghaw, MD, an assistant professor of medicine in the rheumatology division at the Icahn School of Medicine at Mount Sinai Hospital in New York City. "You are basically trying to prevent fusion and stiffening of the ribs."

Here's how to do deep-breathing exercises:

Stand up with your feet hip distance apart and your arms out in front of you at chest height. Your palms should face up. Slowly breathe in and let your arms move up into a U shape — think of tracing the shape of a big wine glass. Hold your breath for a few seconds. Slowly breathe out and lower your arms to the start position.

Dr. Ghaw said to do this first thing in the morning for 20 breaths. You can research different demonstrations of deep breathing for ankylosing spondylitis online.

Both Reveille and Ghaw urge people newly diagnosed with ankylosing spondylitis to start doing deep-breathing exercises and spinal extension exercises right away. "Usually, AS progresses from the lumbar (lower) spine upwards," Ghaw said. "But at this point, we can't predict the rate of progression — everybody's different. We usually ask patients to address the mobility of their entire spine, even at their neck, just to make sure we don't run into disability later on."

In addition to exercises to protect your deep-breathing ability, it's crucial that you don't smoke. Nicotine promotes inflammation and is one of the strongest factors leading to spinal fusion, warned Reveille. If you need help kicking the habit, talk to your doctor.