Causes of smoking:The smoking reduce our life span every person now but again do smoking.Somker not do smoking by happy there are some reason due to which people do smoking which is either related to its mantle condition. Here we see cause of smoking.1) Mantle illnessIllness is also a cause Smoking .In England 42% cigarette use by the person that is mentally disturbed. The use of cigarette is less due to awareness but the rate of use of cigarette is constant in the mentally disturb people.People do smoking due to stress while when sign of smoking appear than they leads to stress. Both these thing work together ( Fluharty M et al.,2016). Smokers believe that smoking is good for brain function . But when they do not do Smoking for a while they feel stress. The study shows that smoking has bad effects on brain and people and cause stress (Taylor G et al.,2014).2) Poverty and smokingThe smoking is also practice due to poverty .The Bangladesh is the poorest country. In Bangladesh 2.8% daily spend is on smoking .1.5% for poor family and 4.5% for rich house. The spend of many on smoking in poor country is also due to stress and anxiety .In Indonesia the use of tobacco is more in poor people ( Beyer J et al.,2001).3) Weight managementOne important reason of smoking is the body fat .when the people gain body fat that leads to many diseases. For the weight management mostly people start smoking. Usually the teenager girl do smoking for body fitness and weight control.Approximately 40% girl start smoking to reduce the hunger in diet plans The weight of nonsmoker is 4-5 kilograms more than Smokers. The people that leave smoking has take weight upto 7-19 ponds while when do smoking gain weight upto 4-5 ponds. The nicotine during the process of smoking effect on nicotine receptors in brain the that increase the chemical breakdown of food while reduce intake of food and thus help in weight management (Audrain-McGovern J et al.2011).4) Nicotine addictionNicotine addiction causes smoking more evidently in youth than older one . Nicotine effect on teenager fastly while it’s effect in older is slow ( MD H J et al.,2016).5) Access to tobaccoAccess to tobacco lead to smoking. Inspite of rule and regulation the cigarette is easily available to Smokers. The age to buy smoking is 18-19 years. While the teenager easily purchase from shops. The student of 6-9 class get cigarette through social relations. Mostly people get cigarette from home, friends and other contact ( MD H J et al.,2016).Pathological effects of smoking:The inauspicious effects of cigarette smoke on health of human are extensively recognized. Vulnerability to tabacco smoke adversely increase the oxidative stress in the body by different mechanism in which include reduction of plasma antioxidants like as vitamin C (Saha S P et al 2007).Tabacoo smoke include more than 7,000 chemicals and toxic compounds.These toxic chemicals and compound arrive the lungs of humans rapidly every time when human inhale this.Then these toxic chemicals carries the blood and next to each organ of the body. A key chemical compound that is responsible for the powerful habit forming effects of cigratte is a Nicotine (Benjamin R.M et al. 2011). Addicting of Nicotine has been established thethe pysochopharmacologic mechanism that retain the cigratte smoking behavior ( Bergen A. W & Caporaso N, 1999).N-nitroso compounds are another significant group of chemicals occur in tobacco smoke. In the urine of smokers this chemical is found (Vineis P , 2008) .Due to smoking relating diseases 50% smokers are die, the expectation of life is reduced by as much as 15 to 20 year one of the four smokers(Gometz E D et al. 2011). In United kigdom 17,000 children are hspitalized every year with the illness of exposure of tobacco smoking under the age of 5 year ( Fagerstrom K, 2002) .Smokers are at a more risk for cardiovascular diseases , respiratory disorders, cancer (lung, pancreas, breast, liver, bladder, oral, larynx, oesophagus, stomach and kidney), peptic ulcers and gastroesophageal reflux disease (GERD) etc( El-Zayadi A R. 2006).1) Cardiovascular effects:The level icreases of heart rate,plasma catecholamine and arterial blood pressure by smoking of cigratte(Jensen -TJ, 1988). The adhernce of platelets increased by smoking.By the contribution of vessel wall changing, it change the shape of tissues, abnormality in blood coagulation increased both these activates the systimic inflammatory signals( Messner B and Bernhard D, 2014).Nicotine in smoking decontrol the autonomic function of heart,increase the rate of heart, cause coronary peripheral vosoconstriction and also stimulate the level of hormone.It also increase the development of atherosclerosis. The atherosclerosis is a arterial changing that rigid and thick all the arteries( Papathanasiou G et al,2018).2) Gastrointestinal effects:On the intragastric instillation on PH 9.8 nicotine was great absorbed at 15 minute mean 18.6 or 3.4%.Side effect of this absorption is the nausea, delay gastric emptying and vomiting occur(Ivey J K & Triggs E.J ,1978).A common disorder of gastrointestinal system is peptic ulcer and it pathogenesis is multifaceted where nicotine and smoking have a remarkable harmful effects.with or without ulcer the gastric secretary capacity is increased greatest in smoker as compared to non smokers.Smoking and nicotine treatment increase the basal acid outputs which is cause the gut ulcer in smokers.nicontine and smoking increase the pepsinogen secretions, increased the number of chief cells and also increased the capacity of secretion.smoking also increase the bile salt and gastric salt that that cause the increasing of duodenogastric reflux that raise mthe high risk of gut ulcer in smokers(Maity P et al, 2003).3) Respiratory system effects:In United state the 80% of all chronic lung diseases responsible by cigrate smoking.By passive smoking, environmental exposure tabbaco smoke increase the risk of heart diseases, lung cancer and respiratory diseases.smoking directly cause inflammation and harm the respiratory tract and developing high risk of lung diseases like pneumonia,chronic bronchitis and influenza(Fagerstrom K, 2002). On respiratory epithelium ciggrate smoking directly effect. Against invasive agents like pollutants, microorganisms and allergens the epithelium coating the upper respiratory tract that act as first line of defense.when the contact of these agents with epithelium cause the several diseases( Tamashiro E , et al, 2009).cigrate smoking directly toxic for cells in the lungs and the repair function of epithelial cells, mesenchyme cells and fibroblasts can damage (Rennard I S et al, 2006).4) Reproduction and growth effect:The fertility rate is lower by cigrate smoking and harm the reproductive system.It is also associated with earlier onset of menupause.By smoking high risk of spontaneous abortions and production of of live birth per cycle become lowered(Dechanet C, et al 2011).smoking also inhibt the production of egg in females, process of fertilization,Embryo implantation, development of fetus during gestation period.It also icrease the risk of pelvic inflammatory diseases(PID), which is unsolved issue in likelihood(Zavos M.P & Zarmakoupis-Zavos N.P, 1999).Smoking cause adverse effect each tissue of the body of human and as well as human semen parameter like motility and volume in smokers ( Al-Turki A.H, 2015).Nicotine that is a harmful chemical that present in the tobacco has been detected in the semen and serum of smoker person. Nicotine lower the viability of spermatozoa percentage and increase the apoptosis of spermatozoa with DNA damage and change the chromatin segments(Bo Dai J, et al. 2015).Harmful effect of smoking (especially nicotine) on the hypothalamic, testicular axis and effect the concentration of testosterone hormone, LH hormone, ACTH hormone, TSH hormone etc(Stillman J. R et al, 1986).