Like other coronaviruses, including those that cause the common cold and that triggered SARS, COVID-19 is a respiratory illness.  

The most common symptoms are: 
Dry cough 
Shortness of breath
Difficulty breathing 
Although having a runny nose doesn't rule out coronavirus, it doesn't thus far appear to be a primary symptom. 

Most people only become mildly ill, but the infection can turn serious and even deadly, especially for those who are older or have underlying health conditions.  

In these cases, patients develop pneumonia, which can cause: 

Potentially with yellow, green or bloody mucus
Fever, sweating and shaking chills
Shortness of breath 
Rapid or shallow breathing 
Pain when breathing, especially when breathing deeply or coughing 
Low appetite, energy and fatigue 
Nausea and vomiting (more common in children) 
Confusion (more common in elderly people)

Some patients have also reported diarrhea and kidney failure has occasionally been a complication. 
Avoid people with these symptoms. If you develop them, call your health care provider before going to the hospital or doctor, so they and you can prepare to minimize possible exposure if they suspect you have coronavirus.