Bronchitis is caused by inflammation in the respiratory tube between the nose and lung. It is often caused by viral infections. It is a symptom of throats, thorns and thorns like throats.
Medical Definition of Common cold. Common cold: A contagious viral upper respiratory tract infection. The common cold can be caused by many different types of viruses, and the body can never build up resistance to all of them. For this reason, colds are a frequent and recurring problem.
Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing. A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia.