3.Cold or Flu
If you have a bad cold, the flu, or some other bug, it can leave you feeling tired and weak. Flu symptoms can linger for up to a couple of weeks. But they should go away once you get better. Some viruses can infect the muscle itself to cause weakness. This isn’t likely to happen if you’re otherwise healthy.
4.COVID-19
COVID-19 signs are often similar to those of the flu and include coughing, fever, and fatigue. But COVID also can cause symptoms in other parts of the body, including muscle weakness. If a bad case of COVID or any other illness keeps you in bed at home or in the hospital for days or weeks, your muscles also will lose strength fast. Physical therapy or exercises you do at home will help you get your strength back.
