What's Causing My Skin to Be Red?
Most marine animal stings and bites are accidental, but their effects may be serious. Symptoms include breathing difficulty, pain and swelling, bleeding, and spasms, among others.
A black widow spider bite may cause redness and swelling in the area of the bite before more serious symptoms develop, including pain in the chest and abdomen, and muscle cramps.
Polycythemia vera is a bone marrow disorder in which the body produces too many red blood cells, possibly leading to clots. This will cause serious symptoms, including deep vein thrombosis.
Autonomic dysreflexia is a condition in which the autonomic (involuntary) nervous system overreacts to a stimulus, causing a spike in blood pressure, racing heart, and changes in other autonomic functions.