Sometimes they can get like this when they are teething. When my son was teething we didn't even notice until a tooth came thru. He never acted any different. My daughter is a whole different story. She had cold symptoms for about 2 months when she first started cutting teeth, runny nose, cough, irratable, occasional fever! She would sometimes even refuse bottles. 7 months is about the age when teething starts, of course it could be weeks before you see a tooth. Normally if it's a cold the dr will tell you to use a cool mist humidifier, elevate the crib mattress at the end where their head is and use baby nasal spray and the aspirator. In most cases they won't give a Rx so it may be a waste of time heading to the dr.