May cause headaches, dizziness and fainting. Others produce more serious symptoms of lightheadedness, dizziness and fainting. Symptoms include excess sweating, excessive hunger, fainting, fatigue, lightheadedness and shakiness. Overdose symptoms include nausea, vomiting, hypotension, hypoventilation, shortness of breath, and fainting. Side effects of popper abuse includes tachycardia, headaches, migraines, dizziness and fainting. Additional symptoms of the condition may include arrhythmia, fainting, and dizziness. Acute heartworm disease in cats can result in shock, vomiting, diarrhea, fainting, and sudden death. Neurological signs include confusion, disorientation, visual disturbance, syncope (fainting), and seizures. Tilt table testing could provoke fainting or syncope. Maria Christina's illness returned and she suffered from serious coughing, fainting and fever. Louisa was sickly, plagued by migraine headaches and frequent fainting spells. Symptoms of a dangerously slow heartbeat include weakness, loss of energy and fainting. Reports of strong audience reactions were widespread; many including accounts of nausea and fainting. The name Syncopy derives from "syncope", the medical term for fainting or loss of consciousness. Syncope, by contrast, is actually fainting.