Respiratory infections are illnesses that affect the airways and lungs, often caused by viruses or bacteria. Common examples include the common cold, influenza, and pneumonia. Symptoms may include coughing, sneezing, sore throat, and difficulty breathing. These infections can spread through droplets when an infected person coughs or sneezes. Most respiratory infections are mild and can be treated at home with rest and fluids. However, some can lead to serious complications, especially in vulnerable populations like the elderly or those with weakened immune systems. Vaccines, such as the flu vaccine, can help prevent certain respiratory infections.