Complications of COVID-19 include long-term loss of taste and smell, skin rashes, and sores. The illness can cause trouble breathing or pneumonia. Medical issues a person already manages may get worse. Complications of severe COVID-19 illness can include: Acute respiratory distress syndrome, when the body's organs do not get enough oxygen. Shock caused by the infection or heart problems. Overreaction of the immune system, called the inflammatory response. Blood clots. Kidney injury.