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.
Symptoms vary depending on the concentration of carbon monoxide in the environment, the length of time you are exposed, and your health. If you are exposed to very high levels of carbon monoxide gas in a poorly ventilated room, you can develop: Headache. Shortness of breath.