As you can see by the picture, rattlesnake bites are not the "two puncture wounds" that are often pictured in old boyscout manuals.
Here is a gallery of other envenomation photos Bite Photos
As many as 50% of bites by rattlesnakes are 'dry bites' where no venom is injected. Many folk remedies for snakebite came about because no venom was injected to begin with.
Symptoms include, but are not limited to pain, severe swelling, bruising, blistering, headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, collapse or convulsions, Yellow vision; paraesthesia/numbness of digits, metallic taste in mouth, fasciculations, and/or death.
1. I am not a doctor, this is not medical advice.
2. This is a constantly evolving article. Do not consider it as being complete or comprehensive.
If bitten by a venomous snake, seek immediate medical care from a qualified and licensed physician.
What happens to your body when a rattlesnake bites you?
Venom, a complex mixture of proteins and enzymes enters your body either subcutaneously or intramuscularly.
Depending on species, any of the following may occur:
Neurotoxins may travel through the lymphatic system and begin to work on your nervous system, causing muscle paralysis.
Hemotoxins begin to break down your blood and tissue.
Nephrotoxins may travel to your kidneys and cause acute tubular necrosis, breaking down the tubes that carry waste from your blood to your bladder.
Cardiotoxins may affect your heart muscles.
Muscle fibers from necrosing flesh may enter your bloodstream and affect your kidneys in a condition called Rhabdomyolysis.
CK (Creatine Kinase) levels in the bloodstream rise because of muscle damage. This is the same thing that happens when one has a heart attack.
The area around the bite fills with excess fluid in a condition called edema. A bruising or discoloration from damaged capillaries occurs called Ecchymoses.
Large blood blisters called hemorraghic blebs, from bleeding under the skin, may form around the bite site.
As your blood cells are destroyed, a condition called thrombocytopenia, the ability of the body to transfer oxygen to the kidneys is reduced, also causing acute tubular necrosis in the kidneys. Blood pressure drops to dangerous levels.
The venom causes fibrinogen in the blood stream to form clots, depleting the blood's supply of fibrinogen. Once these initial clots form, the rest of the blood is without clotting ability and the danger of free-bleeding increases. This is called Disseminated Intravascular Coagulation, or DIC.
"Third Spacing" may occur. This is when intercellular fluids are used by the body to replace water lost through vomiting and diarrhea. The body is essentially re-hydrating itself by using water from inside cells.
In VERY FEW bites, compartmental pressures rise in the affected area causing "compartment syndrome" In these rare cases surgical cuts may be necessary to releive compartmental pressure and allow blood flow through the affected limb, and to decrease the chance of random tearing of tissue. This is EXTREMELY rare, and compartment syndrome is very difficult to distinguish from the normal symptoms of snakebite. Again, this is NOT medical advice, but I can say that IF I were bitten by a rattlesnake and my physician were considering a fasciotomy, I would ask my doctor to measure the compartmental pressures with a tonometer (this is very painful, by the way) and I would only consider giving my permission for a fasciotomy if MY compartmental pressures were greater than 30 mm/hg for two or more hours.
In some cases a severe allergic reaction may occur. Anaphylaxis occurs when the body's immune system begins to over-compensate the production of antibodies in reaction to the presence of a foreign protein. In cases of anaphylactic reactions the person may exhibit hives, cyanosis (a bluish discoloration to the face) swelling of the throat causing an inability to breath, and the possibility of death within minutes.
Involuntary muscle twitching, known as fasciculations may occur.
Make sure to read the article on pre-hospital first aid...
First Aid For Snakebite