Clinical manifestations: 1. Facial swelling, conjunctival congestion, bloody foam in the mouth and nasal cavity, purple skin mucosa, wet and cold limbs, restlessness or unconsciousness, irregular breathing, lung rales, weak and irregular heart sounds, and abdominal distension. 2. The freshwater drowned people have the performance of blood dilution and hemolysis, while the seawater drowned people have the performance of blood concentration and high blood potassium. 3. Death due to cardiac and respiratory arrest in severe cases.