WARNING: The following article contains spoilers for Amazing Spider-Man #76, on sale now.
Peter Parker is is no stranger to dire straits and has survived some of the most brutal battles in the Marvel Universe. But after a run-in with the U-Foes resulted in the hero's radiation poisoning, Peter's greatest threat may be coming from within. His body could heal itself with time, thanks to the benefits of being bitten by a radioactive spider. But the poison in his blood is still a danger to him, a danger that he has become painfully aware of thanks to his Spider-Sense.
The result of this catch-22 is that he is constantly bombarded by intense warnings of danger, the cause of which he knows of but cannot escape until one of his greatest powers places him in a coma. It introduces a new angle to the spider-sense, a danger that could come up again if Peter ever truly got sick.
In Amazing Spider-Man #76 (by Zeb Wells, Patrick Gleason, Marcio Menyz, VC's Joe Caramagna) Peter Parker had been brought to the hospital to recover following an attack by the U-Foes. After Ben Reilly leaves his bedside to confront the villains again, Peter quickly began seizing up. His spider-sense was going into overdrive, overwhelming his senses as it tried to warn him of the danger to himself. But the poison was inside him, and as much as his healing factor was working to reduce the risks he would still need time to heal. That said the threat was so immediate and intense to him that the Spider-sense could not be ignored this time.
It began forcing him to try and get away from a danger that was dwelling in his blood, but Peter could not run from the threat in a conventional sense. This resulted in a startling backup where his body fell into a coma to alleviate the intense symptoms of the spider-sense's adverse reaction.
Traditionally, the spider-sense has been able to warn Peter of almost any type of danger. It doesn't tell him specifically what the danger is, but gives him enough to know that there is a threat to him somewhere. But depending on the immediacy and severity of the threat, the spider-sense can go from a light tingling to intense pain within his head. The deadly amount of radiation poisoning within him must have sent the power into a frenzy, trying to warn Peter of something he is aware of but cannot do anything about.
However, this is the first time that the spider-sense has been shown to be a threat to Peter's health. It's a defense mechanism and it can't determine that a problem can be fixed with time instead of an immediate fight or flight response. It's because of that failing Peter is now suffering the consequences.
This revelation about the ability's dark side also raises some very important questions about the future and what could happen to Peter down the line. This coma was a result of intense radiation poisoning that would have killed an average human quickly, and even Spider-Man needs help to recover from it. Even if Peter is able to recover say he gets sick again, along the lines of cancer or some other illness that requires something like chemotherapy or radiation treatments, his spider-sense may view those as a threat to him.
In some cases, the medical treatment may actually require invasive physical surgery. The spider-sense could wake Peter from the anesthesia while on the table if it recognized the surgeon's incisions as danger. If the Spider-sense isn't able to reconcile itself from Peter's understanding of what is and is not a threat to himself, it may continue to be a danger to him in some circumstances. He may spend the rest of his life at war with an instinct that he has no control over as it tries to force him to flee.