Mild cases of COVID-19 - and the majority of cases are mild - cause symptoms similar to a cold or flu. They include a fever, dry cough and shortness of breath with some patients also reporting a sore throat and headaches.

But in about 20 percent of patients, infections can become more serious. It can attack the lungs, causing an immune system response that can destroy lung tissue and cause inflammation that can then trigger other problems.

"The lack of oxygen leads to more inflammation, more problems in the body. Organs need oxygen to function, right? So when you don't have oxygen there, then your liver dies and your kidney dies," said Dr. Carlos del Rio, a professor of medicine and global health at Emory University.

The following symptoms may appear 2-14 days after exposure.

• Fever

• Cough

• Shortness of breath

Call your doctor

If you think you have been exposed to COVID-19 and develop a fever and symptoms, such as cough or difficulty breathing, call your healthcare provider for medical advice.

If you develop emergency warning signs for COVID-19 get medical attention immediately.

Emergency warning signs include:

• Difficulty breathing or shortness of breath

• Persistent pain or pressure in the chest

• New confusion or inability to arouse

• Bluish lips or face

This list is not all-inclusive. Consult your medical provider for any other symptoms that are severe or concerning.