Pneumonia is a respiratory disease that occurs when the tissues in the lungs (except in the bronchi) get inflamed. This leads to improper functioning of the lungs, as they get filled with pus or mucus. Pneumonia can be caused either by bacteria or virus. In the earlier times, it was one of the leading causes of death in the world. However, with the invention and development of antibiotics and other medications, it was possible to reduce the mortality rate caused by pneumonia. Pneumonia is found to be more common in children and older people than young adults and middle aged people. Causes and Symptoms Pneumonia is commonly caused due to bacteria like Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Haemophilus influenzae, etc. Viruses like Respiratory Syncytial Virus (RSV), Influenza A and B, and Parainfluenza can cause pneumonia. On the other hand, exposure to air pollution, smoke, passive smoking, toxins, hereditary factors, and malnutrition are some of the risk factors leading to pneumonia. The symptoms of pneumonia include difficulty in breathing, shortness of breath, fever, cough, shaking chills, chest pain, headache, fatigue, etc. Walking pneumonia is a type of pneumonia caused by Mycoplasma. It is called so because it is less severe, and hence, people do not need bed rest in it; they can 'walk' around. Treatment It is essential to consult the doctor as early as possible, if one experiences any of the aforementioned symptoms. The treatment of pneumonia depends on the cause. Mycoplasma and bacterial pneumonia are treated with the help of antibiotics. However, antibiotics prove ineffective in treating viral pneumonia. Bed rest and having a lot of fluids is the only effective method of treating viral infection. Pneumonia is caused due to bacteria and viruses that are contagious. Does Pneumonia Remain Contagious after taking Antibiotics? The virus causing pneumonia, cold, influenza, etc., are contagious. This means, that pneumonia can be transmitted from one person to other in the initial phase when a person suffers from cold or influenza. Secondly, Mycoplasma pneumonia or walking pneumonia is contagious. However, pneumonia caused by toxins or smoke is not contagious. After starting antibiotics, pneumonia can be contagious for 48 hours or 2-3 days. Walking pneumonia is contagious for the 2-3 days of taking antibiotics. However, if antibiotics are taken immediately on the onset of the symptoms, the contagious period reduces. One should remember that following habits of cleanliness and hygiene like washing hands before eating, having a bath every day, and having a nutritious and healthy diet helps in preventing this condition to a great extent. Take care! Disclaimer: This Buzzle article is meant only to provide information. It is not to be substituted for doctor's advice.