The first sign of bedbugs may be red, itchy bites on the skin, usually on the arms or shoulders. Bedbugs tend to leave straight rows of bites, unlike some other insects that leave bites here and there.
Bedbugs do not seem to spread disease to people. But itching from the bites can be so bad that some people will scratch enough to cause breaks in the skin that get infected easily. The bites can also cause an allergic reaction in some people. Read more about bedbugs.