 [ Symptoms ] can a 17 year old get arthritis  im 17 with knee pain can i be able to get arthritis this young [ Disease ] a cough in a healthy 4 year old can be many things most commonly colds from viral infections can cause coughs other causes can be allergies post nasal drip and asthma if your child has had the cough for several weeks it is important to speak to your doctor if he has allergies or asthma that is causing this there are medications available to make him feel better call your doctor