The severity of a person's reaction to the bite depends on the area of the body bitten, amount of venom injected, depth of bite, seasonal changes and temperature. The bite feels like a pinprick or is not even felt. At first, there may be only slight local swelling and two faint red spots surrounded by local redness at the bite.

Pain becomes intense in one to three hours and may continue up to 48 hours. Pain usually progresses from the bitten member up or down the arm or leg, finally localizing in the abdomen and back. The abdominal muscles may become rigid and board-like with severe cramps (resembles appendicitis). There may be pain in the muscles and soles of the feet and eyelids may become swollen.

Other symptoms may be nausea, profuse perspiration, tremors, labored breathing, labored speech and vomiting. During this time, a feeble pulse, cold clammy skin, unconsciousness, convulsions and even death may result if the victim does not receive medical attention immediately.

Additional complications may occur due to the infection of the bite. However, with some untreated individuals, symptoms may diminish in several hours and be gone completely after several days of agony.

Bites are uncommon and serious long-term complications or deaths are rare. Only four deaths were officially attributed to black widow bites in the United States from 1960-69.