Common symptoms include a fever, cough, runny nose, headache or body aches, a sore throat and diarrhea. CDC updates and shortens recommended isolation and quarantine period for general population [Press release]. The blood-brain barrier is a packed layer of cells that creates a barrier, protecting molecules in the blood from the brain's blood vessels. The results showed that 68% of patients had one nasal symptom, including dryness and having a "strange" nasal sensation. This is a rapidly evolving area, Blumberg said. That's called an antigen testing. As more Americans get tested for the new coronavirus and the disease it causes, COVID-19, they're discovering the test involves a deep nasal swab that can be uncomfortable . Difficulty breathing or shortness of breath. It is virtually impossible for swab testing to access or have any impact on the blood-brain barrier. Certain lingering respiratory symptoms are signs that a patient recovering from COVID-19 still may test positive for SARS-CoV-2, a new study suggests. But getting to nasopharynx can be uncomfortable as the testing swab has to move through four inches of soft, sensitive tissues. A sample collected from the middle or shallow parts of nose is less likely to detect the virus. So if it feels like theres a half a foot being stuck up your nose, well, youre not so far off. Still, CDC data showed the most common symptoms so far are cough, fatigue, congestion and a runny nose. Sure Signs You May Have Post-Acute COVID Syndrome, Says Doctor . Best food forward: Are algae the future of sustainable nutrition? Nasal or nose swab testing for COVID-19 is a completely standard and safe procedure to detect COVID-19.