Smoking

Nicotine is a stimulant that activates the pleasure center in the brain. When obtained through smoking, nicotine can increase energy and concentration and decrease appetite. Once a person is addicted, smoking will reduce symptoms of nicotine withdrawal and may feel relaxing. People not used to nicotine may have nausea, flushing, or both.

People who handle large amounts of tobacco leaves may absorb nicotine through their skin and develop nausea, vomiting, diarrhea, sweating, and weakness. This illness has been termed green tobacco sickness.

Children who eat tobacco products or nicotine gum or ingest e-liquid can develop nausea, vomiting, diarrhea, sweating, and weakness, along with agitation and confusion, sometimes from as little as one cigarette. However, serious or fatal toxicity in children is uncommon, in part because the vomiting empties the stomach.

The leading smoking-related health problems are the following:

Smoking also increases the risk of stroke Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction). Symptoms occur suddenly... read more , other cancers (such as bladder Bladder Cancer Most bladder cancers are of a type called transitional cell because they affect the same kinds of cells (transitional cells) that are usually the cancerous cells responsible for cancers of the... read more , cervical Cervical Cancer Cervical cancer develops in the cervix (the lower part of the uterus). Most cervical cancers are caused by human papillomavirus (HPV) infection. Cervical cancer usually results from infection... read more , colorectal Colorectal Cancer Family history and some dietary factors (low fiber, high fat) increase a person’s risk of colorectal cancer. Typical symptoms include bleeding during a bowel movement, fatigue, and weakness... read more , esophageal Esophageal Cancer Esophageal cancers develop in the cells that line the wall of the esophagus (the tube that connects the throat to the stomach). Tobacco and alcohol use, human papillomavirus infections, and... read more , kidney Kidney Cancer Most solid kidney tumors are cancerous, but purely fluid-filled tumors (cysts) generally are not. Almost all kidney cancer is renal cell carcinoma. Another kind of kidney cancer, Wilms tumor... read more , liver Hepatocellular Carcinoma Hepatocellular carcinoma is a cancer that begins in the liver cells and is the most common of the primary liver cancers. Having hepatitis B or hepatitis C or fatty liver disease, or drinking... read more , pancreatic Pancreatic Cancer Smoking, chronic pancreatitis, male sex, being Black, and possibly long-standing diabetes are risk factors for pancreatic cancer. Abdominal pain, weight loss, jaundice, and vomiting are some... read more , throat Mouth and Throat Cancer Mouth and throat cancers are cancers that originate on the lips, the roof, sides, or floor of the mouth, tongue, tonsils, or back of the throat. Mouth and throat cancers may look like open sores... read more , and stomach Stomach Cancer A Helicobacter pylori infection is a risk factor for stomach cancer. Vague abdominal discomfort, weight loss, and weakness are some typical symptoms. Diagnosis includes endoscopy and biopsy... read more ), pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more and other respiratory infections, asthma Asthma Asthma is a condition in which the airways narrow—usually reversibly—in response to certain stimuli. Coughing, wheezing, and shortness of breath that occur in response to specific triggers are... read more , osteoporosis Osteoporosis Osteoporosis is a condition in which a decrease in the density of bones weakens the bones, making breaks (fractures) likely. Aging, estrogen deficiency, low vitamin D or calcium intake, and... read more , periodontitis (gum disease) Periodontitis Periodontitis is a severe form of gingivitis, in which the inflammation of the gums extends to the supporting structures of the tooth. Plaque and tartar build up between the teeth and gums and... read more , peptic ulcer disease Peptic Ulcer Disease A peptic ulcer is a round or oval sore where the lining of the stomach or duodenum has been eaten away by stomach acid and digestive juices. Peptic ulcers can result from infection with Helicobacter... read more , cataracts Cataract A cataract is a clouding (opacity) of the lens of the eye that causes a progressive, painless loss of vision. Vision may be blurred, contrast may be lost, and halos may be visible around lights... read more , erectile dysfunction Erectile Dysfunction (ED) Erectile dysfunction (ED) is the inability to attain or sustain an erection satisfactory for sexual intercourse. (See also Overview of Sexual Dysfunction in Men.) Every man occasionally has... read more , and fertility problems Overview of Infertility Infertility is usually defined as the inability to achieve a pregnancy after 1 year of regular sexual intercourse without birth control. Frequent intercourse without birth control usually results... read more .

People who do not smoke but who are exposed to smoke from a burning cigarette or the smoke exhaled by a nearby smoker (passive, or secondhand smoking) can develop many of the same disorders as smokers, particularly with repeated and sustained exposure. The Surgeon General concluded there is no safe level of secondhand smoke exposure.

Children exposed to cigarette smoke lose more school days because of illness than nonexposed children.

The toxicity of smokeless tobacco can vary from one brand to another. Risks include heart and blood vessel disorders, mouth disorders (for example, cancers Mouth and Throat Cancer Mouth and throat cancers are cancers that originate on the lips, the roof, sides, or floor of the mouth, tongue, tonsils, or back of the throat. Mouth and throat cancers may look like open sores... read more , gum recession Gum Recession Gum recession is the loss of tissue at the gumline with exposure of the root of the tooth. Recession usually occurs in thin, delicate gum tissue or in response to overaggressive toothbrushing... read more , gingivitis Gingivitis Gingivitis is a mild form of periodontal disease characterized by inflammation of the gums (gingivae). Gingivitis results most often from inadequate brushing and flossing but may result from... read more , and periodontal disease Periodontitis Periodontitis is a severe form of gingivitis, in which the inflammation of the gums extends to the supporting structures of the tooth. Plaque and tartar build up between the teeth and gums and... read more and its consequences), and tumors.

E-cigarettes or vape pens Vaping Vaping refers to inhaling vapor (volatilized liquid) produced by battery-powered devices. The vapor can contain nicotine, tetrahydrocannabinol (THC) and cannabinoid (CBD) oils, and other substances... read more are devices consisting of a battery and a cartridge containing an atomizer to heat a solution, often with nicotine. Long-term risks of e-cigarettes are unknown.

Smoking can interact with other drugs. The effects are largely due to tars in the liver as a by-product of smoking and not due to the nicotine; hence, most effects are not seen with nicotine replacement therapy (NRT). Smoking dries and wrinkles a person's skin, thins the hair, and turns the teeth and fingers yellow. Smokers tend to weigh about 10 pounds less than they would if they did not smoke, but not everyone gains weight when they quit smoking. Also, the harmful effects of smoking far outweigh the risks of weight gain. Employees who smoke cost employers on average over $5,000 more per year than nonsmoking employees due to greater health care costs and more missed days of work. Smoking increases the risk of unemployment and makes it harder to find re-employment.

Nicotine withdrawal Nicotine Withdrawal While often very challenging, quitting smoking is one of the most important things smokers can do for their health. Quitting smoking brings immediate health benefits that increase over time... read more may result in many unpleasant symptoms, including a craving for nicotine, irritability, anxiety, poor concentration, restlessness, trembling (tremor), depressed mood, weight gain, headaches, drowsiness, and stomach upset. Withdrawal is most troublesome in severely dependent people. The symptoms of nicotine withdrawal peak in the first 3 days and subside over 2 to 4 weeks, but some symptoms, such as craving, may continue longer.