Aeroembolism is the presence of air in the blood vessels of the body. Direct entry of air into the veins may occur through trauma, cannulation (see cannula), or surgery, and a large air embolus reaching the heart may cause death. In acute decompression (as with flying to high altitude or sudden surfacing after deep diving) bubbles of air come out of solution. These may block small blood vessels, causing severe muscle pains ("bends"), tingling, and chocking sensations, and occasionally paralysis or coma. Recompression and slow decompression is the correct treatment.