Twisting the knee is a common cause of overstretched or torn ligaments of the knee. The knee may give out suddenly when the ACL is torn and there may be a popping sound upon injury. Symptoms of a torn ACL include knee pain, swelling, stiffness, and bruising.
Early symptoms of carbon monoxide poisoning such as headaches, nausea, and fatigue, are often mistaken for the flu because the deadly gas goes undetected in a home. Prolonged exposure can lead to brain damage and even death.
Breathing in carbon monoxide can cause flu-like symptoms including headaches, dizziness, weakness, vomiting, chest pain, and confusion. It can also make people feel tired or pass out, and can eventually be fatal. RELATED: 5 Plants That Can Help Purify Indoor Air, According to Science.