A system senses various physiological parameters of a patient such as heart rate or temperature to evaluate the patient and predict when an episode of a chronic symptom may occur. The system further includes a modeling component which generates an individualized predictive model for a given patient wherein the patient's previous episodes of the symptom are utilized to shape the model. The system tests the model to assure accuracy and can revise the model as necessary. Once the model is established, the system monitors patient parameters and can alert the patient to the expected onset of the symptom and/or automatically administer an appropriate drug or other therapy to control the expected symptom. The system is applicable to allergic reactions, anxiety attacks, attention deficit hyperactivity disorders, backaches, depression, dizziness, drowsiness, epileptic seizures, fatigue, heart malfunction, hunger pangs, joint or other pain, loss of motor control, migraines, motion sickness, muscle spasm, nausea, nicotine fits, numbness, shaking, shortness of breath, sleep or sleep disorders, tremors, unconsciousness, vision impairment or other chronic symptoms.