1.The tobacco plant is capable of producing toxic chemical alkaloids (including nicotine), which it uses to protect against insect pests. When an insect tries to eat a plant, it becomes ill because nicotine acts on certain receptors in the brain and interferes with the transmission of nerve impulses. Eventually the pest dies.
Humans also have such receptors, but nicotine affects us differently. Once ingested through cigarettes, it activates our reward system in the brain, dopamine levels increase in the body, so people who use nicotine begin to feel happier and more focused.
Due to the fact that people enjoy the feeling of full concentration and high spirits, many of them begin to use nicotine more and more often. However, with long-term consumption, the reward system in the brain stops functioning as before. The body gets used to the fact that there is now more conventional “happiness”, which means it needs to adapt brain cells to this.
some of them are reduced. When a person stops smoking, the body’s own reserves to maintain concentration and “happiness” are no longer enough, so the body requires a new portion of nicotine - this is the physiology of addiction.



2.Over time, nicotine changes the way your brain works. Therefore, a smoker constantly needs nicotine just to feel normal.

When a person quits smoking, the brain becomes irritable. Some people feel anxious or have a worse mood. People may find it difficult to concentrate or sleep, feel uncomfortable, and have a strong desire to smoke a cigarette.
These sensations may disappear or diminish a few weeks after quitting as the brain becomes accustomed to the absence of nicotine. However, 75% of people who quit smoking return to it within the next year. According to experts, this is due to the fact that smoking and its effect on the brain simply physiologically reduces the ability to enjoy something.



3.When a person smokes a cigarette, pipe or cigar, most of the smoke does not enter the lungs, but is released into the air around them, where anyone nearby can inhale it.

Exposure to second-hand smoke (second-hand smoke) causes approximately 41,000 non-smoking adult deaths and 400 infant deaths annually.secondhand smoke increases the risk of getting the same diseases as regular smokers. For example, if a person has never smoked and does not smoke, but he has a friend or spouse who smokes next to him, then the risk of developing lung cancer in such people increases by about 25%.

Children are especially vulnerable to the effects of secondhand smoke. A child exposed to secondhand smoke has an increased risk of developing respiratory infections, meningitis, a persistent cough, and increased asthma symptoms. In turn, passive smoking among infants increases the risk of sudden infant death syndrome.



4.Smoking affects the condition of the lungs because a person inhales not only nicotine, but also a huge number of other chemical compounds. It is a factor in the development of lung cancer, while increasing the risk of this disease by 25 times or higher compared to non-smokers.

The Centers for Disease Control and Prevention reports that 9 out of 10 deaths from respiratory cancer are related to smoking. This bad habit also increases the risk of developing and dying from chronic obstructive pulmonary disease (COPD).Smoking destroys the small air sacs in the lungs (alveoli), which facilitate oxygen exchange in the body. Damage to the alveoli and interalveolar septa leads to the development of emphysema, which is already an irreversible disease. In other words, the alveoli do not regenerate over time, so smoking causes a person to destroy part of their lungs for life.



5.Smoking cigarettes harms the heart, blood vessels and blood cells. Chemical compounds and tars in cigarettes increase the risk of developing atherosclerosis (plaques forming in the blood). These accumulations can restrict blood flow and increase the risk of other dangerous consequences.

The likelihood of peripheral artery disease is also increased by smoking. According to a meta-analysis by the UK Institute of Health, there is a correlation between smoking and the development of peripheral artery disease (PAD). Research shows that former smokers are at higher risk of developing artery problems than people who have never smoked.Наличие ЗПА увеличивает риски возникновения:

Having PAD increases the risk of:

arterial thrombosis,

angina or chest pain,

stroke,

heart attack.



6.Smoking harms a woman's reproductive system, as the chemicals contained in cigarettes suppress the body's hormones.

Estrogen levels in women decrease, which leads to dry skin and thinning hair. Women who constantly smoke have a harder time getting pregnant and giving birth to a healthy baby. The bad habit also contributes to early menopause, which increases the likelihood of progression of certain diseases (for example, problems with the cardiovascular system).

For men, smoking increases the likelihood of developing erectile dysfunction and other problems over time. Heavy and occasional smoking affects sperm quality and generally reduces fertility.



7.According to the CDC, smoking affects pregnancy and fetal development in a variety of ways:

- increases the likelihood of ectopic pregnancy;

- contributes to low birth weight of the child;

- increases the risk of premature birth;

- damages the lungs, brain and central nervous system of the fetus;

- increases the risk of sudden infant death syndrome;

- contributes to the appearance of congenital anomalies in the fetus, such as cleft lip or cleft palate.
If a partner or someone close to a pregnant woman smokes, the smoke can affect the health of both the woman and the baby before and after birth. Passive smoking contributes to low birth weight babies and increases the risk of sudden infant death syndrome. Babies whose parents smoke are more likely to be hospitalized with bronchitis or pneumonia during the first year of life.



8.People who smoke regularly have a 30-40% higher risk of developing type 2 diabetes than those who do not. Smoking can also make it more difficult for people with this condition to manage their health and worsen its course.



9.Smoking cigarettes weakens a person's immune system, making him more susceptible to disease. It also contributes to the occurrence of additional inflammatory processes in the body.



10.increases the risk of developing cataracts and age-related macular degeneration. Other eye problems associated with smoking include:

- dry eyes,

- glaucoma,

- diabetic retinopathy.


11.People who smoke are twice as likely to have gum and oral disease. The risk itself increases with the number of cigarettes, cigarettes and tobacco smoked.

Symptoms of oral diseases usually include:

- inflammation and soreness of the gums,

- bleeding when brushing your mouth,

- loose teeth,

- increased sensitivity of teeth.

Smoking tobacco products for a long time limits some people's ability to taste and smell foods and some other things. Cigarettes and products and their components can stain teeth yellow or brown.



12.Smoking tobacco harms human skin and hair. Smokers experience premature skin aging. Tobacco smoke can be absorbed into the skin and hair, affecting hair loss and promoting baldness.



Cigarette smoking contributes to the development of other forms of cancer (not just lung cancer). The American Cancer Society (ACS) states that smoking has a significant impact on the development of pancreatic cancer.

People with this bad habit are three times more likely to develop bladder cancer. Smoking cigarettes can double the risk of stomach cancer, and the risk of developing breast cancer in women also increases.

Tobacco smoking increases the risk of developing:

mouth cancer

laryngeal cancer,

throat cancer,

esophageal cancer,

kidney cancer,

cervical cancer,

liver cancer,

colon cancer and other types.