Signs and symptoms of acute exposure to hydrogen sulphide may include tachycardia (rapid heart rate) or bradycardia (slow heart rate), hypertension (high blood pressure), cyanosis (blue tint to skin and mucous membrane), cardiac palpitations; and cardiac arrhythmias. Dyspnoea (shortness of breath), tachypnoea (rapid respiratory rate), bronchitis, pulmonary oedema; respiratory depression; respiratory paralysis may occur. Neurological effects include giddiness, irritability, drowsiness, weakness, confusion, delirium, amnesia, headache, sweating, and dizziness. Muscle cramping, tremor, excessive salivation; cough, convulsions, and coma may be noted. Nausea, vomiting, and diarrhoea are commonly seen. Exposure to hydrogen sulphide gas may result in skin irritation, lachrymation, inability to detect odours, photophobia (heightened sensitivity to light), and blurred vision.