 [ Symptoms ] is there a specific ingredient i should avoid in children is cough and cold medicine  i bought children is triaminic cough and cold with active ingredients dextromethorphan hbr and phenylephrine hcl [ Disease ] if you just started walking this could be normal until your body gets used to the new exercising however if you are very active and are having a great deal of discomfort you should see your doctor the feeling of your heart as if it is being held or squeezed is not a normal reaction that does not mean it is serious or life threatning by any means but it certainly means you should consult with your physician at only 14 yrs of age you should not be experiencing this and if you are saying this occurs with only walking a very short distance you really need to see your doctor