1) Frequent respiratory and viral diseases. If a person caught a cold a couple of times a year and had them cured without any complications, it’s considered normal. Only few can avoid infections while being in a crowd of sneezing and coughing people.
However, many people get sick not just 1-2 times or even 4-6 times, but much more frequently – up to 10 times. Coming to work once recovered, they pick up the infection again and get complications, simultaneously infecting others.