As a child, I heard the old saying "good night, sleep tight; don't let the bed bugs bite". Bed bugs were a rare occurrence when I was a child, but they have grown in numbers.
They are more than a mere annoyance. They can cause itchy skin which leads to a secondary infection. They are often treated with antihistamines and steroids to reduce the itchiness and inflammation.
At least there is some good news; bed bugs are NOT known to transmit any infectious diseases.
Step one - remove your sheets from you bed. Look for dark spots on the mattress. These may be:
Step two - examine your skin. Do you have small red bites? And the bites are really itchy!
Step three - lift your mattress off of your bed. Do you see any small dark spots? You probably will not see the bugs themselves. They scurry away.
Step four - lay out some double sided tape on your bare mattress and leave it there for a few days. If you have a bed bug infestation, you should find a couple stuck to the tape.
Step five - remove the cushions from your couch. Look for small dark spots or the bed bug's waste products.
Step six - take a flashlight to bed with you. Set your alarm for just before dawn. You may be able to catch them in the act by awakening then and then examining your skin and sheets.
Step seven - go to your spice cabinet. Pick up and open the coriander. Smell it. This is what a really large infestation smells like.
Step eight - return to your bed. And with the sheets still off, sniff you mattress. Does the smell remind you of coriander?
If you find bed bugs, call an exterminator. Do not attempt to eradicate them without help.