Conversation: The conversation between human and AI assistant.
[|Human|] Hello, I am 13 years old and healthy but yesterday night after I walked around a lot I have chest pains on my left side along with  my left arm and its been a day and still it hurts. It feels like pressure and seems to get better when I lay down? My heart is fast? Help, what do I do?
[|AI|]  Hello thanks for posting here. Seems like muscular pain to me because of prolonged walking leading to generation of lactic acid. But other causes should be excluded. One is heart disease, which in view of your age i don't suspect. Second is a lung infection which can cause above symptoms. You have not mentioned any cough or fever history or any weight loss so I presume they are not present. Still i would advice you a chest x-ray to see if there is any lung involvement. Meanwhile, you can be on a short course (5 days) of painkiller medications and antacids. Regards