<P> The main signs and symptoms of cystic fibrosis are salty - tasting skin, poor growth, and poor weight gain despite normal food intake, accumulation of thick, sticky mucus, frequent chest infections, and coughing or shortness of breath . Males can be infertile due to congenital absence of the vas deferens . Symptoms often appear in infancy and childhood, such as bowel obstruction due to meconium ileus in newborn babies . As the children grow, they exercise to release mucus in the alveoli . Ciliated epithelial cells in the person have a mutated protein that leads to abnormally viscous mucus production . The poor growth in children typically presents as an inability to gain weight or height at the same rate as their peers, and is occasionally not diagnosed until investigation is initiated for poor growth . The causes of growth failure are multifactorial and include chronic lung infection, poor absorption of nutrients through the gastrointestinal tract, and increased metabolic demand due to chronic illness . </P> <P> In rare cases, cystic fibrosis can manifest itself as a coagulation disorder . Vitamin K is normally absorbed from breast milk, formula, and later, solid foods . This absorption is impaired in some cystic fibrosis patients . Young children are especially sensitive to vitamin K malabsorptive disorders because only a very small amount of vitamin K crosses the placenta, leaving the child with very low reserves and limited ability to absorb vitamin K from dietary sources after birth . Because factors II, VII, IX, and X (clotting factors) are vitamin K--dependent, low levels of vitamin K can result in coagulation problems . Consequently, when a child presents with unexplained bruising, a coagulation evaluation may be warranted to determine whether an underlying disease is present . </P> <P> Lung disease results from clogging of the airways due to mucus build - up, decreased mucociliary clearance, and resulting inflammation . Inflammation and infection cause injury and structural changes to the lungs, leading to a variety of symptoms . In the early stages, incessant coughing, copious phlegm production, and decreased ability to exercise are common . Many of these symptoms occur when bacteria that normally inhabit the thick mucus grow out of control and cause pneumonia . In later stages, changes in the architecture of the lung, such as pathology in the major airways (bronchiectasis), further exacerbate difficulties in breathing . Other signs include coughing up blood (hemoptysis), high blood pressure in the lung (pulmonary hypertension), heart failure, difficulties getting enough oxygen to the body (hypoxia), and respiratory failure requiring support with breathing masks, such as bilevel positive airway pressure machines or ventilators . Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa are the three most common organisms causing lung infections in CF patients . In addition to typical bacterial infections, people with CF more commonly develop other types of lung disease . Among these is allergic bronchopulmonary aspergillosis, in which the body's response to the common fungus Aspergillus fumigatus causes worsening of breathing problems . Another is infection with Mycobacterium avium complex, a group of bacteria related to tuberculosis, which can cause lung damage and does not respond to common antibiotics . People with CF are susceptible to getting a pneumothorax . </P> <P> Mucus in the paranasal sinuses is equally thick and may also cause blockage of the sinus passages, leading to infection . This may cause facial pain, fever, nasal drainage, and headaches . Individuals with CF may develop overgrowth of the nasal tissue (nasal polyps) due to inflammation from chronic sinus infections . Recurrent sinonasal polyps can occur in 10% to 25% of CF patients . These polyps can block the nasal passages and increase breathing difficulties . </P>

Most common cause of pneumonia in cystic fibrosis
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