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.
Here are some of the most common signs of carbon monoxide: A yellow, large and unsteady natural gas appliance burner flame (with the exception of decorative natural gas log appliances). An unusual pungent odor when the appliance is operating.