special subjects
Smoking and Other Tobacco Use
Symptoms and Signs of Tobacco Use
Nicotineslightly increases heart rate, blood pressure, and respiratory rate. People who smoke may feel increased energy and arousal, increased ability to concentrate, decreased tension and anxiety, and a sense of pleasure and reward. Nausea is common on a person's first exposure tonicotine.Nicotinereduces appetite and can be a behavioral substitute for eating.Nicotine's effects are transient given its short half-life. If not repeatedly dosed, the individual experiences the effects ofnicotinewithdrawal including lethargy, difficulty concentrating, restlessness, anxiety, tension, depressed mood, irritability, and hunger. With combustible tobacco, exercise tolerance tends to decrease because of respiratory tract irritation. Low-grade carbon monoxide toxicity can also limit exercise tolerance, but this is probably only a factor in elite athletes. Acutenicotinepoisoning is usually caused by oral (eg, children eating a cigarette ornicotinegum or ingesting e-liquid) or dermal (eg, handling raw tobacco products) exposure, rather than smoking. Mildnicotinetoxicity,as is common with green tobacco sickness and minor ingestions by children (eg, < 1 cigarette or 3 butts), typically manifests with nausea, vomiting, headache, and weakness. Symptoms spontaneously resolve, usually in 1 to 2 hours after ingestion if poisoning is mild; however, symptoms can persist for 24 hours if poisoning is severe. Severenicotinepoisoningcauses a cholinergic toxidrome with nausea, vomiting, salivation, lacrimation, diarrhea, urination, fasciculations, and muscle weakness. Patients usually have crampy abdominal pain and, if poisoning is very severe, arrhythmias, hypotension, seizures, and coma. The fatal dose ofnicotineis approximately 60 mg in nonsmoking adults, 120 mg in adults who smoke, and as little as 10 mg in young children. Each cigarette contains approximately 8 mg ofnicotine(only about 1 mg is absorbed by smoking). However, the amount ingested by children is usually difficult to ascertain by history because ingestion is rarely observed; any ingestion should be considered potentially dangerous. Findings due to smoking itself include yellow stains of teeth and fingers, and in comparison to age-matched controls, weight is slightly lower (≤ 5 kg difference), skin is drier and more wrinkled, and hair is thinner. Other symptoms are those of smoking-related lung and cardiovascular disease. Chronic cough and dyspnea on exertion are common. Circulatory and respiratory impairments decrease exercise tolerance, often resulting in a more sedentary lifestyle and thus further lowering of exercise tolerance. Smoking cessation often causes intense Nicotine Withdrawal , primarily a craving for cigarettes but also other symptoms (eg, anxiety, difficulty concentrating, sleep disruption, depression) and eventual weight gain. 