The most common symptom of ankylosing spondylitis (AS) is low back pain that develops so gradually you may not notice it in the early stages.
If you've had low back pain for more than three months, see your doctor to have it checked out.
Other signs and symptoms of ankylosing spondylitis include the following:
- Neck pain
- Stiffness that is worse in the morning
- Buttock pain that shifts from side to side
- A reduction in pain and stiffness with physical activity
- A hunched posture
- Difficulty taking a deep breath (if the disease has affected the ribs)
While ankylosing spondylitis most commonly affects the spinal joints, it can also affect other joints in the body, such as these:
- Small joints of the hands and feet
Like other forms of inflammatory arthritis, ankylosing spondylitis tends to flare up from time to time.
As a result, you may have periods with few symptoms alternating with periods of more severe pain and stiffness.
AS Symptoms and the Musculoskeletal System
As noted, ankylosing spondylitis can affect all parts of the spine and numerous joints in addition to those of the spine. The pain in AS most commonly arises from enthesitis, or inflammation where the tendons, ligaments, and bones meet.
Can Ankylosing Spondylitis Affect the Neck?
According to the Arthritis Foundation, ankylosing spondylitis mostly affects the low back or buttocks, but it can move into the upper spine and neck, or cervical spine. In AS, the joints and ligaments along the spine become inflamed, which produces the pain and stiffness. (1)
Some research studies have found that women with AS report neck pain more frequently than men with the condition, but certainly, men with AS can have neck pain and stiffness, too. (2)
Can Ankylosing Spondylitis Cause Herniated Disks?
No. While you can have both ankylosing spondylitis and herniated disks, AS does not cause herniated disks. According to Harris H. McIlwain, MD, a rheumatologist in Tampa, Florida, if you have both, you have two different conditions.
Can Ankylosing Spondylitis Cause Chest Pain?
Adults with ankylosing spondylitis often have a type of chest pain called costochondritis, which is caused by inflammation of the cartilage that connects the breastbone to the ribs.
The pain of costochondritis can imitate an acute heart attack or pleurisy, an inflammation of the tissues that line the lungs and chest cavity. The pain of pleurisy worsens with breathing, coughing, or sneezing. However, the pain of costochondritis can also worsen with deep breathing and upper body movement.
Another possible source of chest, and sometimes abdominal, pain in people with ankylosing spondylitis is inflammation of the joints where the ribs connect to the vertebrae, according to the University of Maryland Medical Center. (3)
Can Ankylosing Spondylitis Affect the Knees?
According to the Spondylitis Association of America (SAA), ankylosing spondylitis causes knee symptoms in about 20 percent of people who have it. The SAA also states that knee pain may actually be “referred pain” from the hips, meaning that the effects of AS inflammation in the hips are felt in the knees but the knee joints themselves aren’t inflamed. (4)
A study published in 2017 in The Eurasian Journal of Medicine noted that changes in the spine caused by AS may also change the normal positioning of a person’s hips and knees when they stand. All of these postural changes taken together may negatively affect a person’s balance. (5)
Non-Joint-Related Symptoms of Ankylosing Spondylitis
Not all of the symptoms of ankylosing spondylitis concern the bones, joints, tendons, and ligaments.
Can Ankylosing Spondylitis Cause Constipation?
Irritable bowel syndrome (IBS) with diarrhea or constipation is found in about 30 percent of people with ankylosing spondylitis, according to a study published in June 2015 in the Annals of the Rheumatic Diseases. People with ankylosing spondylitis may have any of the four types of IBS: (6)
- Alternating diarrhea and constipation type
- Constipation dominant type
- Diarrhea dominant type
- Mixed type
The study found the prevalence of IBS to be significantly higher in women with ankylosing spondylitis than in men.
Can Ankylosing Spondylitis Cause Nausea?
Up to 50 percent of people with AS have microscopic inflammation in the intestinal tract, according to a study published in July 2014 in Current Opinions in Rheumatology. Such microscopic inflammation may or may not cause gastrointestinal symptoms, but when it does, it can include nausea, abdominal pain, chronic diarrhea, and weight loss. (7)
People with ankylosing spondylitis are also at higher risk for inflammatory bowel disease (IBD), according to a study published in May 2019 in Advances in Therapy. IBD includes ulcerative colitis and Crohn’s disease, and Crohn’s disease, in particular, can cause nausea. (8)
Can Ankylosing Spondylitis Affect the Brain?
Fatigue is one of the key symptoms of ankylosing spondylitis, and a study published in January 2014 in Arthritis & Rheumatology showed that fatigue in AS is associated with structural abnormalities in certain areas of the brain collectively known as the “attention system.” However, the study did not show that AS causes these abnormalities nor that the abnormalities are directly responsible for the fatigue experienced by people with AS. (9)
But speaking of fatigue, in a study published in November 2017 in Nature Reviews Neurology, researchers observed that while fatigue is challenging for both doctors and patients, it must be taken seriously because it interferes with patients’ daily activities, has a negative impact on quality of life, and often leads to early retirement. (10)
Can Ankylosing Spondylitis Cause Numbness?
A very rare complication of ankylosing spondylitis, called cauda equina syndrome, can cause severe low back pain as well as numbness in the low back, buttocks, crotch area, and legs. Feelings may range from pins and needles to complete numbness, according to the American Association of Neurological Surgeons. (11)
Cauda equina syndrome occurs when nerve roots at the bottom of the spine are compressed, most often from a herniated disk. In addition to pain and numbness, the syndrome may cause weakness in the legs that makes it difficult to walk as well as bladder, bowel, or sexual dysfunction.
Cauda equina syndrome is considered a medical emergency and usually requires urgent surgery.
Can Ankylosing Spondylitis Cause Tiredness?
Fatigue or tiredness is a common problem with ankylosing spondylitis, according to the Spondylitis Association of America. Inflammation causes fatigue in many arthritis types, and if the inflammation is widespread, the body uses a lot of energy to manage it. Also, when cytokines (cell messengers) are released during the inflammatory process, the sensation of fatigue or tiredness is greatly magnified. (12,13)
Fatigue with ankylosing spondylitis can also be the result of sleep deprivation because of poorly managed pain. Your doctor can help you manage the tiredness associated with ankylosing spondylitis. Be sure to be open with your healthcare team about your symptoms and feelings.
Ankylosing Spondylitis and Eye Inflammation
Ankylosing spondylitis sometimes causes a type of inflammation in the eye called uveitis or iritis.
Symptoms of uveitis include the following:
- Redness and pain in the eye
- Sensitivity to light
- Blurred vision
Seek prompt medical attention if you have significant eye pain or any changes in vision. Untreated uveitis can cause swelling and tissue damage in the eye.
Additional reporting by Debra Fulghum Bruce, PhD.