Because teething is so common and other symptoms such as fever, fussiness, colds, and diarrhoea are also common, both conditions may often occur at the same time. Teething may not be causing these symptoms. Other illnesses or disorders (for example, viral infections) are much more likely to be causing fever, fussiness, nasal congestion with cough, and diarrhoea. It is important to contact your doctor if these or other symptoms seem concerning to you. Do not assume that they are just from the teething.