Panic attack symptoms come on suddenly and are unexpected. The symptoms can be severe and disabling, and those who experience panic attacks may lead to the development of irrational fears (phobias) of certain situations. Panic attack symptoms can be varied and may cause the sufferer to feel that death or a catastrophic event is imminent. Racing heart (palpitations), chest pains, dizziness, difficulty breathing, trembling, stomach upset, hot flashes, chills, terror, altered perceptions, and nervousness are symptoms that are often reported. The symptoms of panic attack may mimic those of a physical illness, such as heart attack. The length of a panic attack can vary, but most attacks tend to last longer than 10 minutes.