When bites occur, only a small amount of venom is injected. The symptoms caused by the venom may seem slight at first. There is usually little or no swelling involved, and it is rare for any nearby lymph nodes to be affected. The most important symptoms are a rapid breakdown of skeletal muscle tissue and paralysis. Early symptoms include headache, a thick-feeling tongue, thirst, sweating, and vomiting. Symptoms that can occur after 30 minutes to several hours after the bite include generalized aching, stiffness, and tenderness of muscles all over the body. This is followed later on by symptoms typical of other elapid attacks: a progressive paralysis of muscles. Paralysis of muscles involved in swallowing and respiration can be fatal. After three to eight hours, myoglobin may start to show up in the blood plasma. This is a result of muscle breakdown. It can cause the urine to turn a dark reddish, brown, or black in color, and eventually lead to kidney failure. After six to twelve hours, severe hyperkalemia can lead to cardiac arrest. The hyperkalemia is also the result of muscle breakdown.