Examples include the following: Some malabsorptive disorders: Gastrointestinal tract surgery and cystic fibrosis Chronic inflammatory disorders: Severe rheumatoid arthritis Gastrointestinal disorders: Achalasia, celiac disease, Crohn disease, chronic pancreatitis, esophageal obstructive disorders, ischemic colitis, diabetic enteropathy, peptic ulcer disease, progressive systemic sclerosis, ulcerative colitis (late) Severe, chronic heart and lung disorders: Chronic obstructive pulmonary disease (COPD), heart failure (stage III or IV), restrictive lung disease Mental disorders (known and poorly controlled): Anxiety, bipolar disorder, depression, schizophrenia Neurologic disorders: Amyotrophic lateral sclerosis, dementia, multiple sclerosis, myasthenia gravis, Parkinson disease, stroke Social problems: Poverty, social isolation With chronic kidney disease and heart failure, accumulation of edema may mask loss of lean body weight.