I want to know mainly about how dangerous the venom really is, somewhere it even said that if you dont get to the hospital in 20 minutes as an adult, you're dead, I find that a little hard to believe, but I guess you guys will tell me.
Well, first of all that source was a gross exaggeration. If you have been informed that "if you get bitten by a widow, you're as good as dead," then you have been misinformed.
This is a big subject, but here's the skinny in a nutshell: they're bad, but not nearly as bad as urban legends say. Without treatment, bites carry a 4 - 6 % chance of fatality, when observed across a wide range of victims, and depending on the species of widow spider ( there are numerous widow spider types, not just one ). Elderly folk, children, and persons with compromised vital systems ( respiratory, cardiac, neurologic, etc. ) are the most at risk, and have a death rate higher than the 4 - 6 %. On the other hand, healthy, strong adults in the 20 - 45 yr or so range have a lower death rate than the 4 - 6 %. Five percent is the rough figure when all health and age categories of bitten persons are taken and averaged together.
That was for UNTREATED bites. The reality is that we have excellent antivenom available that cures the symptoms in minutes--if you aren't allergic to either the venom or the antivenom. Allergies to both antivenom and the bite itself are possible, and both are dangerous. If you are allergic to the serum, but not the bite, the antivenom could kill or endanger you. But if you are allergic to the venom itself, your lifespan drops to a few minutes without immediate anti-allergenic first aid.
Antivenom is not given in all cases of widow envenomation, because of the risk of a reaction to it, and because often times you can ride out the bite without it. Non-antivenom treatments can alleviate your suffering while avoiding antivenom, and many bites don't become a life-threatening situation. Serum is given as a last resort, when your life is truly in danger.
As far as what the venom does to you, it is definitely a bad experience. The venom, even when not fatal, is usually agonizing. Widow venom is neurotoxic, meaning it attacks via the nervous system. In this case, the venom tells your nerves to release the neuromuscular stimulant acetylcholine. This activates your muscles, causing them to contract...bigtime. Your body's major muscles all cramp into excruciatingly painful charlie-horses. Your abdominal, leg, back, chest, and arm muscles can all seize up with wood-like rigidity. This cramping also affects the diaphragm, which can become partially or even mostly paralyzed, causing difficulty breathing. The heart is also affected, and becomes shallow and rapid, perhaps irregular in its rhythm. All of this causes one major problem: lack of oxygen. At the same time your breathing and blood-flow are decreased, your muscles are using up massive amounts of oxygen in their out-of-control contractions. In strong envenomations, this results in hypoxia, and you can die of simple oxygen deprivation, or in rare cases, of heart failure.
Most cases don't progress to a life-threatening level--only 1 in 20 are fatal, all things averaged ( though of course, more bites are life-threatening than actually life-ending ). More often than not, however, the envenomation is strong enough to cause very painful cramping, nausea, dizziness, weakness, and other forms of suffering. But you *generally* aren't in danger of your life. HOWEVER, the smart victim (or friend of victim ) will still seek immediate medical attention for a suspected widow bite. You don't know how serious your own bite experience will be, and allergies to widow venom will not show themselves until the bite actually happens--so take that possibility seriously.
Overall, black widows are certainly dangerous, and capable of causing the occasional fatality, if treatment is unavailable. With antivenom treatment available, no deaths have been recorded in quite some time, but that is still NO reason to take them lightly. Even with antivenom available, a black widow bite can be a harrowing experience ( especially since the serum isn't administered until absolutely necessary ).