When you inhale smoke, you take in substances that can damage your lungs. Over time, your lungs lose their ability to filter harmful chemicals. Coughing can't clear out the toxins sufficiently, so these toxins get trapped in the lungs. Smokers have a higher risk of respiratory infections such as colds, flu and pneumonia.
In a condition called emphysema, the air sacs in your lungs are damaged. In chronic bronchitis, the lining of the tubes of the lungs becomes inflamed. Over time, smokers are at increased risk of developing these forms of chronic obstructive pulmonary disease (COPD). Long-term smokers are also at increased risk of lung cancer.
Withdrawal from tobacco products can cause temporary congestion and respiratory pain as your lungs begin to clear out.
Children whose parents smoke are more prone to coughing, wheezing, and asthma attacks than children whose parents don't. They also tend to have more ear infections. Children of smokers have higher rates of pneumonia and bronchitis.