@madhusudhan Hello, Walking pneumonia is often caused by a type of bacterium that produces milder symptoms that come on more gradually than do those of other types of pneumonia. The illness often is brought home by young children who contract it at school. Symptoms generally start 15 to 25 days after you’re exposed to mycoplasma and slowly get worse over 2 to 4 days. Symptoms include chest pain, sore throat, and headache. Many over-the-counter medicines for cold and flu may not relieve all of your symptoms. If anyone has the symptoms mentioned above should talk to her doctor. Thank You!!!!