Besides the well-known medical problems individuals can develop as a result of weight gain (high blood pressure, diabetes, cancer, stroke, and heart disease), extra weight puts additional stress on joints and bones. For example, the corticosteroid prednisone causes weight gain to some degree in nearly all patients who take the medication and can lead to redistribution of body fat to places like the face, back of the neck, and abdomen.
On the other hand, underweight people can suffer from medical problems, ranging from chronic fatigue and anemia to lowered resistance to infection and clinical depression. Inflammation, certain medications, and depression associated with a chronic illness may lessen your appetite or upset your stomach, making it difficult for some people with spondylitis to maintain a healthy weight. This is especially true for those who have spondylitis with inflammatory bowel disease or Crohn’s disease who experience gastrointestinal problems on top of arthritis symptoms. Any severe weight loss to should be reported to your doctor.