Tonic-clonic seizures, also known as grand mal seizures, are a type of generalized seizure that affects the entire brain. They typically involve two phases: the tonic phase, where the body becomes stiff and the person may lose consciousness, followed by the clonic phase, characterized by rhythmic jerking movements of the limbs. These seizures can last from a few seconds to several minutes. During a tonic-clonic seizure, individuals may experience a loss of awareness and may not remember the event afterward. Common symptoms include muscle rigidity, shaking, and sometimes biting the tongue. It is important to seek medical attention if seizures occur frequently or if they are the first seizure experienced.