The existence of salty sweat and skin is due to the defects of the CFTR protein, thus, the inability for chloride to be transported around the body. Therefore, the chloride is excreted through sweat which creates abnormally salty sweat for CF patients. The characteristic thick mucus in CF patients causes cilia inside the lungs to become unable to sweep the pathogen-filled mucus out of the mucus linings inside the lungs, thus, the buildup of pathogens and the decreased ability for air to travel through the lungs. This creates frequent lung infections and wheezing or shortness of breath. 
The buildup of mucus in the pancreas leads to the inability for this organ to produce vital digestive enzymes, bicarbonate, and insulin that play into digestion, the absorption of nutrients  for the body, and assisting in the transport of glucose from the blood into the cells for energy. Thus, poor growth and weight gain and Cystic Fibrosis related Diabetes is common for CF patients. Additionally, mucus in CF patients can block the pancreatic duct which leads to the inability for enzyme to transport to the small intestines. Thus, poor digestion and greasy stool is common for CF patients. Male CF patients sometimes have an absence of vas deferens in the reproductive system. The vas deferens connects the epididymis (located behind the testes) to the penis. Thus, the absence of the vas deferens means the inability for the sperm to transfer during discourse. This is why male fertility occurs in CF patients. This condition is called the congenital bilateral absence of the vas deferens or CBAVD. 
The severity of CF symptoms can vary throughout patients.