Strokes. Loss of smell. COVID toes.

As the list of unusual symptoms linked to COVID-19 continues to expand, scientists have mounting evidence that COVID-19 disease is more than a respiratory illness that primarily affects the lungs. In many patients, the virus also attacks the vascular system, the some 60,000 miles worth of blood vessels—arteries, veins and capillaries—that run throughout our body.

Researchers currently believe COVID-19 disease is able to cause such wide-reaching damage due its entry method into cells that differs from other respiratory viruses: It uses its “protein spike” to grab hold of receptors on ACE2 (angiotensin converting enzyme-2) cells. ACE2 receptors are not only found in the nose, throat and lungs, but are also prominent in the cells that line blood vessels, as well as the kidneys, the gastrointestinal tract and the heart. “Unfortunately, ACE2 receptors are spread throughout the body,” says Jay Purdy, MD, PhD, a Vice President and lead in Anti-Infectives, Global Medical Affairs at Pfizer, adding “wherever the virus can attach, it will attack.” Experts currently believe that the vascular effects of COVID-19 disease are twofold: it attacks the blood vessels that line various organs, such as the lung, heart and kidneys, and also causes widespread inflammation and clots. People with COVID-19 disease experience a broad range of symptoms—from mild symptoms, or none at all, to those requiring hospitalization. Scientists are still trying to understand why some people develop severe symptoms.

Read onto learn more about the wide-ranging vascular symptoms of COVID-19.