Spider bites

Most spider bites are such minor puncture wounds that there may be no bleeding. Read about the treatment of small wounds  here and about the treatment of spider bites here.

Non-sensationalistic information on spider bites can be found at the following linked sites for the five kinds of spiders whose bites can cause serious problems. (Only two of the five are native to the U.S.)

Widow spiders (especially the two species commonly called "black widows") National Institutes of Health  MedlinePlus

Recluse spiders (especially the species most often found in the U.S. and commonly called "brown recluses") National Institutes of Health MedlinePlus

Tarantulas (of which only a few imported species give bites severe enough to require medical treatment) National Institutes of Health MedlinePlus (for species native to the U.S. only) For sometimes commercially imported tarantulas giving severe (but not life-threatening) bites see section 3 of the paper by Escoubas and Rash at this link.

Australian funnel-web spiders, National Institutes of Health  MedlinePlus (I have not been able to find any reports of these spiders stowing away in shipments to other countries.)

Brazilian armed spiders Rick Vetter, University of California at Riverside. (These spiders sometimes show up in shipments of bananas or other produce, as do look-alike species.)