Symptoms may include dizziness, weakness, trembling, palpitations, seizures, confusion, headache, drowsiness, coma, diaphoresis and nausea. Inhaling "p"-xylene can cause dizziness, headache, drowsiness, and nausea. Common side effects include vomiting, constipation, itchiness, lightheadedness, and drowsiness. They include drowsiness, dizziness, and decreased alertness and concentration. Major symptoms include fever, headache, nausea and vomiting, confusion, vision impairment, drowsiness, seizures and coma. Common side effects include nausea and drowsiness. Severe overexposure may cause weakness, drowsiness, and unconsciousness. Common side effects include drowsiness, vomiting, and constipation. Young children often exhibit only nonspecific symptoms, such as irritability, drowsiness, or poor feeding. It may cause drowsiness or unconsciousness if inhaled. Symptoms of arsenic poisoning begin with headaches, confusion, severe diarrhea, and drowsiness. Caffeine is a central nervous system stimulant that reduces fatigue and drowsiness. Side effects associated with its use include drowsiness and headaches. Using ACDU, a patient is assessed for alertness, confusion, drowsiness, and unresponsiveness. The most common effects of overdose are drowsiness and tachycardia.