include difficulty breathing, wheezing (a whistling sound when you breathe), and chest pain. Exacerbations of symptoms may occur, these exacerbations occur more frequently in advanced or severe disease. Systemic symptoms, including fevers, chills, night sweats, fatigue and weight loss may be seen with bronchiectasis. Bronchiectasis may also present with coughing up blood in the absence of sputum, which has been called "dry bronchiectasis." Exacerbations in bronchiectasis present as a worsening of cough, increasing sputum volume or thickened consistency lasting at least 48 hours, worsening shortness of breath (breathlessness), worsening exercise intolerance, increased fatigue or malaise and the development of hemoptysis. People often report frequent bouts of "bronchitis" requiring therapy with repeated courses of antibiotics. People with bronchiectasis may have bad breath from active infection. On examination, crepitations and expiratory rhonchi may be heard with auscultation. Nail clubbing is a rare symptom. The complications of bronchiectasis include serious health conditions, such as respiratory failure and atelectasis: collapse or closure of a lung. Respiratory failure occurs when not enough oxygen passes from the lungs into the blood. Atelectasis occur when one or more segments of the lungs collapse or do not inflate properly. Other pulmonary complications include lung abscess and empyema. Cardiovascular complications include cor pulmonale, in which there is enlargement and failure of the right side of the heart as a result of disease of the lungs. Causes There are many causes that can induce or contribute to the development of bronchiectasis. The frequency of these different causes varies with geographic location. Cystic fibrosis is identified as a cause in up to half of cases. Bronchiectasis without CF is known as non-CF bronchiectasis. Historically, about half of all case of non-CF bronchiectasis were found to be idiopathic, or without a known cause. However, more recent studies with a more thorough diagnostic work-up have found an etiology in 60 to 90% of patients. Cystic fibrosis Cystic fibrosis is the most common life-threatening autosomal recessive disease in the United States and Europe. It is a genetic disorder that affects the lungs, but also the pancreas, liver, kidneys, and intestine. It is caused by mutations in the CFTR protein, a chloride channel expressed in epithelial cells. Lung disease results from clogging of the airways due to mucus build-up, decreased mucociliary clearance, and resulting inflammation. In later stages, changes to the structure of the lung, such as bronchiectasis, occur. Around 5 to 10% of all