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.
The prognosis depends on the severity of carbon monoxide poisoning. Among people with severe symptoms, as many as two out of three people may have long-term complications, especially neurological problems. In people with mild to moderate symptoms, as many as one in five can develop lasting neurological problems.