The Bite Wound
There is no symptomatic pain when a blue-ringed octopus bites, apart from a small pinch that some victims do not feel. Therefore, the only way to discern if there is a bite without seeing it happen is to see the wound. The area around the site of the bite becomes lighter after the octopus bites a human victim. A blood blister may also form at the site.
Paralysis
The venom of a blue-ringed octopus is the neuromuscular toxin tetrodotoxin or maculotoxin. The characteristic symptom of this neurotoxin is paralysis. A victim's nerves will stop functioning soon after the bite, which leads to an inability to move. It also causes organs, such as the lungs, to cease functioning. This helps it catch its small prey, but is also effective in humans. The blue-ringed octopus is immune to its venom.
Paresthesia
The victim will feel tingling around the lips and on the tongue anywhere from 15 minutes to a few hours after a blue-ringed octopus bites a human. This will progress into itching, burning or tingling of the face, arms, legs, hands and feet. These are the parts of the body that will lose movement first. The brain and organs follow and then death occurs between four and 24 hours after the bite.
Pain
The bite of a blue-ringed octopus may not hurt save for a small pinch, but the venom can be painful. One of the early symptoms of a blue-ringed octopus bite is stomach pain. Later, the respiratory system fails, cardiac function is affected and the victim may have seizures. Any of these symptoms may cause pain for the victim.
Other Symptoms
Victims of blue-ringed octopus bites will start to produce excess saliva. They will also begin to have stomach ailments, apart from pain. There is nausea, vomiting and diarrhea before paralysis sets in.