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.
Low level carbon monoxide poisoning symptoms may include any combination of the following: A more unusual carbon monoxide poisoning symptom is an unexplained sense of a presence or something is watching. Many ghost houses have been found to have carbon monoxide leaks - usually from cracks/partial blockages in old chimneys and faulty boilers.