My 4 month has fever and diahreah and runny nose and is sweating. is it a common cold or teething?

Likely infectious: The symptoms sound more infectious. Teething should not cause diarrhea and a runny nose necessarily. If the infection persisits, get your 4 month old examined by the doctor, as infants can dehydrate easily, especially with fevers and diarrhea. Good luck.

Possibly: When a baby is teething they can feel miserable and have a slight feve, runny nose and other mile cold symptoms. But this may also be a cold. So the best thing to do is to treat the cold symptoms with lots of fluids and tylenol (acetaminophen) if the fever is high. Lots of hugs and special attention for you baby.

Maybe: I can be hard to determine the exact cause of an infants symptoms... It might be related to teething or it might be a cold. Please monitor your child closely and give palliative care: 1. Cold compresses 2. Children's tylenol (acetaminophen) per the label's directions. 3. Maintain hydration, plain water is ok. 4. Call your pediatrician if the fever increases or persists for more than 3 days.