The of nicotine is 50 mg/kg for rats and 3 mg/kg for mice. 0.5-1.0 mg/kg can be a lethal dosage for adult humans, and 0.1 mg/kg for children. However the widely used human LD estimate of 0.5–1.0 mg/kg was questioned in a 2013 review, in light of several documented cases of humans surviving much higher doses; the 2013 review suggests that the lower limit causing fatal outcomes is 500–1000 mg of ingested nicotine, corresponding to 6.5–13 mg/kg orally. An accidental ingestion of only 6 mg may be lethal to children.

It is unlikely that a person would overdose on nicotine through smoking alone. The US Food and Drug Administration (FDA) stated in 2013: "There are no significant safety concerns associated with using more than one [over the counter] OTC [nicotine replacement therapy] NRT at the same time, or using an OTC NRT at the same time as another nicotine-containing product—including a cigarette." Ingestion of nicotine pharmaceuticals, tobacco products, or nicotine containing plants may also lead to poisoning. Smoking excessive amounts of tobacco has also led to poisoning; a case was reported where two brothers smoked 17 and 18 pipes of tobacco in succession and were both fatally poisoned. Spilling an extremely high concentration of nicotine onto the skin can result in intoxication or even death since nicotine readily passes into the bloodstream following skin contact.

The recent rise in the use of electronic cigarettes, many forms of which are designed to be refilled with nicotine-containing "e-liquid" supplied in small plastic bottles, has renewed interest in nicotine overdoses, especially in the possibility of young children ingesting the liquids. A 2015 report on e-cigarettes by Public Health England noted an "unconfirmed newspaper report of a fatal poisoning of a two-year old child" and two published case reports of children of similar age who had recovered after ingesting e-liquid and vomiting. They also noted case reports of suicides by nicotine. Where adults drank liquid containing up to 1,500 mg of nicotine they recovered (helped by vomiting), but an ingestion apparently of about 10,000 mg was fatal, as was an injection. They commented that "Serious nicotine poisoning seems normally prevented by the fact that relatively low doses of nicotine cause nausea and vomiting, which stops users from further intake." Four adults died in the US and Europe, after intentionally ingesting liquid. Two children, one in the US in 2014 and another in Israel in 2013, died after ingesting liquid nicotine.

The initial treatment of nicotine poisoning may include the administration of activated charcoal to try to reduce gastrointestinal absorption. Treatment is mainly supportive and further care can include control of seizures with the administration of a benzodiazepine, intravenous fluids for hypotension, and administration of atropine for bradycardia. Respiratory failure may necessitate respiratory support with rapid sequence induction and mechanical ventilation. Hemodialysis, hemoperfusion or other extracorporeal techniques do not remove nicotine from the blood and are therefore not useful in enhancing elimination. Acidifying the urine could theoretically enhance nicotine excretion, although this is not recommended as it may cause complications of metabolic acidosis.

Green Tobacco Sickness (GTS) is a type of nicotine poisoning caused by the transdermal absorption of nicotine from the surface of wet tobacco plants. Tobacco harvesters, whose clothing becomes saturated from tobacco wet with rain or morning dew, are at high risk of developing GTS. Workers can avoid getting this sickness by waiting to harvest until the tobacco leaves are dry, or by wearing a rain suit. Wet clothing that has come in contact with tobacco leaves should be removed immediately and the skin washed with warm soapy water.

Nicotine from other sources, including nicotine gum, a nicotine patch or electronic cigarette, or other tobacco products like cigarettes or smokeless tobacco, appears to reduce the risk of GTS due to the body adapting to the intake of nicotine.

Symptoms of GTS include nausea, vomiting, headache, dizziness, and severe weakness. These symptoms may be accompanied by fluctuations in blood pressure or heart rate. Abdominal cramping, chills, increased sweating, salivation and difficulty breathing are also common. The illness will resolve on its own within one to two days, but symptoms may be so severe as to require emergency medical treatment.

Worldwide there are an estimated 33 million tobacco farm workers, with a substantial proportion living in developing countries. A recent international review reported that between 8-89% of tobacco harvesters may be affected in the course of a season (this wide variation probably being due to differences between study methodologies as well as a range of working conditions). The long-term health outcomes for individuals exposed to nicotine transdermally for extended periods of time are not known.

Education and counselling by physicians of children and adolescents has been found to be effective in decreasing the risk of tobacco use.

The administration of oxygen as a medical intervention is common in diving medicine, both for first aid and for longer term treatment.

Dipping tobacco, commonly referred to as snuff, is also put in the mouth, but it is a flavored powder. it is placed between the cheek and gum. Dipping tobacco doesn't need to be chewed for the nicotine to be absorbed into your body. First-time users of these products often become nauseated and dizzy. Long-term effects include bad breath, yellowed teeth, and an increased risk of oral cancer.

Users of dipping tobacco are believed to face less risk of some cancers than smokers but are still at greater risk than people who do not use any tobacco products. They also have an equal risk of other health problems directly linked to nicotine such as increased rate of atherosclerosis.

Recompression treatment in a hyperbaric chamber was initially used as a life-saving tool to treat decompression sickness in caisson workers and divers who stayed too long at depth and developed decompression sickness. Now, it is a highly specialized treatment modality that has been found to be effective in the treatment of many conditions where the administration of oxygen under pressure has been found to be beneficial. Studies have shown it to be quite effective in some 13 indications approved by the Undersea and Hyperbaric Medical Society.

Hyperbaric oxygen treatment is generally preferred when effective, as it is usually a more efficient and lower risk method of reducing symptoms of decompression illness, However, in some cases recompression to pressures where oxygen toxicity is unacceptable may be required to eliminate the bubbles in the tissues that cause the symptoms.

A method to increase pilot resistance to airsickness consists of repetitive exposure to the flying conditions that initially resulted in airsickness. In other words, repeated exposure to the flight environment decreases an individual’s susceptibility to subsequent airsickness. Recently, several devices have been introduced that are intended to reduce motion sickness through stimulation of various body parts (usually the wrist).

Human milk sickness is uncommon today in the United States. Current practices of animal husbandry generally control the pastures and feed of cattle, and the pooling of milk from many producers lowers the risk of tremetol present in dangerous amounts. The poison tremetol is not inactivated by pasteurization. Although extremely rare, milk sickness can occur if a person drinks contaminated milk or eats dairy products gathered from a single cow or from a smaller herd that has fed on the white snakeroot plant. There is no cure, but treatment is available.

Travelers who are susceptible to motion sickness can minimize symptoms by:

- Choosing a window seat with a view of the ground or of lower clouds, such that motion can be detected. This will not work if the plane is flown in the clouds for a long duration.

- Choosing seats with the smoothest ride in regards to pitch (the seats over the wings in an airplane). (This may not be sufficient for sensitive individuals who need to see ground movement)

- Sitting facing forward while focusing on distant objects rather than trying to read or look at something inside the airplane.

- Eating dry crackers, olives or suck on a lemon, to dry out the mouth, lessening nausea.

- Drinking a carbonated beverage.

Increased water intake may also help in acclimatization to replace the fluids lost through heavier breathing in the thin, dry air found at altitude, although consuming excessive quantities ("over-hydration") has no benefits and may cause dangerous hyponatremia.

The only reliable treatment, and in many cases the only option available, is to descend. Attempts to treat or stabilize the patient "in situ" (at altitude) are dangerous unless highly controlled and with good medical facilities. However, the following treatments have been used when the patient's location and circumstances permit:

- Oxygen may be used for mild to moderate AMS below and is commonly provided by physicians at mountain resorts. Symptoms abate in 12 to 36 hours without the need to descend.

- For more serious cases of AMS, or where rapid descent is impractical, a Gamow bag, a portable plastic hyperbaric chamber inflated with a foot pump, can be used to reduce the effective altitude by as much as . A Gamow bag is generally used only as an aid to evacuate severe AMS patients, not to treat them at altitude.

- Acetazolamide 250 mg twice daily dosing assists in AMS treatment by quickening altitude acclimatization. A study by the Denali Medical Research Project concluded: "In established cases of acute mountain sickness, treatment with acetazolamide relieves symptoms, improves arterial oxygenation, and prevents further impairment of pulmonary gas exchange."

- The folk remedy for altitude sickness in Ecuador, Peru and Bolivia is a tea made from the coca plant. See mate de coca.

- Steroids can be used to treat the symptoms of pulmonary or cerebral edema, but do not treat the underlying AMS.

- Two studies in 2012 showed that Ibuprofen 600 milligrams three times daily was effective at decreasing the severity and incidence of AMS; it was not clear if HAPE or HACE was affected.

Gradually reducing nicotine intake causes less withdrawal than abruptly stopping. Another way to reduce nicotine withdrawal symptoms is to provide the body with an alternative source of nicotine (nicotine replacement therapy) for a temporary period and then taper this new nicotine intake. Other medication used for quitting smoking include bupropion, varenicline, cytisine, nortriptyline, and clonidine. Treatments other than medication, such as increased exercise, can also reduce nicotine withdrawal. Many behavior changes such as avoiding situations where one usually smoked, planning ahead to deal with temptations, and seeking the support of friends and family are effective in helping people quit smoking, but whether this is due to reduced withdrawal is unclear.

Fertilisers like ammonium phosphate, calcium ammonium nitrate, urea can be supplied. Foliar spray of urea can be a quick method.

Most daily cigarette smokers have at least one of the above withdrawal symptoms when they try to stop. Withdrawal can occur in less-frequent users, however heavier users and those with a past or current psychiatric disorder tend to have more severe withdrawal. Genetics also influence the severity of withdrawal.

The most widely used potassium fertilizer is potassium chloride (muriate of potash). Other inorganic potassium fertilizers include potassium nitrate, potassium sulfate, and monopotassium phosphate. Potassium-rich treatments suitable for organic farming include feeding with home-made comfrey liquid, adding seaweed meal, composted bracken, and compost rich in decayed banana peels. Wood ash also has high potassium content. Adequate moisture is necessary for effective potassium uptake; low soil water reduces K uptake by plant roots. Liming acidic soils can increase potassium retention in some soils by reducing leaching; practices that increase soil organic matter can also increase potassium retention.

There are effective treatments for nicotine dependence, although the majority of the evidence focuses on treatments for cigarette smokers rather than people who use other forms of tobacco (e.g., chew, snus, pipes, hookah, electronic cigarettes). These treatments have been shown to double or even triple a smoker’s chances of quitting successfully.

The disease appears in the ER episode "Great Expectations", where the symptoms are not recognized by Dr. Carter.

There are eight major evidence-based medications for treating nicotine dependence: bupropion, cytisine (not approved for use in some countries, including the US), nicotine gum, nicotine inhaler, nicotine lozenge/mini-lozenge, nicotine nasal spray, nicotine patch, and varenicline. These medications have been shown to significantly improve long-term (i.e., 6-months post-quit day) abstinence rates, especially when used in combination with psychosocial treatment. The nicotine replacement treatments (i.e., patch, lozenge, gum) are dosed based on how dependent a smoker is—people who smoke more cigarettes or who smoke earlier in the morning use higher doses of nicotine replacement treatments.

Abdominal discomfort begins two to six hours after eating unripe ackee fruit, followed by sudden onset vomiting. In severe cases, profound dehydration, seizures, coma, and death may ensue. Children and those who are malnourished are more susceptible to the disease.

There is a lack of good evidence to support the use of any particular intervention for morning sickness.

Immediate treatment with 100% oxygen, followed by recompression in a hyperbaric chamber, will in most cases result in no long-term effects. However, permanent long-term injury from DCS is possible. Three-month follow-ups on diving accidents reported to DAN in 1987 showed 14.3% of the 268 divers surveyed had ongoing symptoms of Type II DCS, and 7% from Type I DCS. Long-term follow-ups showed similar results, with 16% having permanent neurological sequelae.

Some studies support the use of ginger, but overall the evidence is limited and inconsistent. Safety concerns have been raised regarding its anticoagulant properties.

Apart from stopping the habit, no other treatment is indicated. Long term follow-up is usually carried out. Some recommend biopsy if the lesions persists more than 6 weeks after giving up smokeless tobacco use, or if the lesion undergoes a change in appearance (e.g. ulceration, thickening, color changes, especially to speckled white and red or entirely red). Surgical excision may be carried out if the lesion does not resolve.

All plants require sufficient supplies of macronutrients for healthy growth, and nitrogen (N) is a nutrient that is commonly in limited supply. Nitrogen deficiency in plants can occur when organic matter with high carbon content, such as sawdust, is added to soil. Soil organisms use any nitrogen to break down carbon sources, making N unavailable to plants. This is known as "robbing" the soil of nitrogen. All vegetables apart from nitrogen fixing legumes are prone to this disorder.

Nitrogen deficiency can be prevented in the short term by using grass mowings as a mulch, or foliar feeding with manure, and in the longer term by building up levels of organic matter in the soil. Sowing green manure crops such as grazing rye to cover soil over the winter will help to prevent nitrogen leaching, while leguminous green manures such as winter tares will fix additional nitrogen from the atmosphere.