Only approach the cat if it is necessary to do so, such as a trip to the vet. The majority of agitated cats benefit from being left in peace, rather than being petted or picked up. If you do have to approach the cat, the very first thing you need to do when your cat is upset is to protect yourself and then the cat. Scared or aroused cats can and will bite their owners and they will scratch. This displaced aggression means your cat is so upset that it will bite or scratch anyone handy if it cannot get at the object or thing making it upset.  It is imperative that you approach your upset cat with extreme caution. Approach the cat cautiously, preferably wearing long sleeves and pants. Have a towel handy in case you need to catch your cat. Talk to your cat calmly. For example, say "It's okay, Peaches, it's okay. Shh. Shh." Sit quietly and wait for your cat to calm down, and let it realize you mean it no harm and don't pose a threat.  Speak quietly and in a lower pitched voice. Singing can soothe or relax your cat, much like talking quietly. Singing anything from an upbeat song to a slow melody can work. Just don't sing loudly, harshly, or anything with rapidly changing pitches. Play something softly on the TV. Feed your cat some food if it is still skittish. Wet food is usually more appealing to cats than dry food and fish has an even greater odor than meat.  Let the cat climb to a higher place to allow it to feel safe and able to see what is going on. If possible, stroke the cat's face by running your thumb lightly up from the bridge of the cat's nose. Placing the cat in a confined space where it can be alone should help it to calm itself down. Close all doors to the area your cat is in, close shades, blinds, or drapes on windows so it cannot see outside. Remove children and other pets from the area as well. The aim is to provide a calm, non-threatening environment so that cat's anxiety levels fall. To move the cat to a room it can be alone in, wrap the cat in a towel snuggly with only its head sticking out,...

TL;DR in Vietnamese:
Bảo đảm an toàn cho cả bạn lẫn mèo trước. Nói chuyện nhẹ nhàng và hành động chậm rãi. Nhử mèo tiến lại gần bạn. Cách ly mèo nếu chúng vẫn cảm thấy lo lắng.