how vape can damege you

 An electronic cigarette, also called vape^{[note 1][1]} is a device that simulates tobacco smoking. It consists of an atomizer, a power source such as a battery, and a container such as a cartridge or tank filled with liquid. Instead of smoke, the user inhales vapor.^[2] As such, using an e-cigarette is often called "vaping".^[3] The atomizer is a heating element that vaporizes a liquid solution called e-liquid,^[4] which quickly cools into an aerosol of tiny droplets, vapor and air.^[5] E-cigarettes are activated by taking a puff or pressing a button.^[3][6] Some look like traditional cigarettes,^[3][7] and most kinds are reusable.^{[note 2]} The vapor mainly comprises propylene glycol and/or glycerin, usually with nicotine and flavoring. Its exact composition varies, and depends on several things including user behavior.^{[note 3]}

Vaping is likely far less harmful than smoking, but still harmful.^[9][10][11] E-cigarette vapor contains fewer toxins than cigarette smoke. It contains traces of harmful substances not found in cigarette smoke.^[11]

Nicotine is highly addictive.^[12][13][14] Users become physically and psychologically dependent.^[15] Scientists do not know how harmful e-cigarettes are over the long-term^[16][17] because it is hard to separate the effects of vaping from the effects of smoking when so many people both vape and smoke.^{[note 4][18]} E-cigarettes have not been used widely enough or for long enough to be sure.^[19][20][21]

For people trying to quit smoking, e-cigarette use alongside prescribed nicotine replacement therapy (NRT) leads to a higher quit rate.^[22][23] For those trying to quit smoking without medical help, it is not clear whether e-cigarettes raise quit rates because As of 2015, research had not yet provided a consensus on the risks of e-cigarette use.^{[155][51][154]} There is little data about their safety, and a considerable variety of liquids are used as carriers,^[168] and thus are present in the aerosol delivered to the user.^[82] Reviews of the safety of e-cigarettes have reached quite different conclusions.^[169] A 2014 WHO report cautioned about potential risks of using e-cigarettes.^[170] Regulated US FDA products such as nicotine inhalers may be safer than e-cigarettes,^[125] but e-cigarettes are generally seen as safer than combusted tobacco products^[88][95] such as cigarettes and cigars.^[88]

The risk of early death is anticipated to be similar to that of smokeless tobacco.^[171] Since vapor does not contain tobacco and does not involve combustion, users may avoid several harmful constituents usually found in tobacco smoke,^[172] such as ash, tar, and carbon monoxide.^[173] However, e-cigarette use with or without nicotine cannot be considered risk-free^[174] because the long-term effects of e-cigarette use are unknown.^{[21][161][171]}

Possible side effects of nicotine^[175]

The cytotoxicity of e-liquids varies,^[176] and contamination with various chemicals have been detected in the liquid.^[33] Metal parts of e-cigarettes in contact with the e-liquid can contaminate it with metal particles.^[172] Many chemicals including carbonyl compounds such as formaldehyde can inadvertently be produced when the nichrome wire (heating element) that touches the e-liquid is heated and chemically reacted with the liquid.^[177] Normal usage of e-cigarettes,^[122] and reduced voltage (3.0 V^[2]) devices generate very low levels of formaldehyde.^[177]

The later-generation and "tank-style" e-cigarettes with a higher voltage (5.0 V^[176]) may generate equal or higher levels of formaldehyde compared to smoking.^[3] A 2015 report by Public Health England found that high levels of formaldehyde only occurred in overheated "dry-puffing".^[178] Users detect the "dry puff" (also known as a "dry hit"^[179]) and avoid it, and they concluded that "There is no indication that EC users are exposed to dangerous levels of aldehydes."^[178] However, e-cigarette users may "learn" to overcome the unpleasant taste due to elevated aldehyde formation, when the nicotine craving is high enough.^[180]

Another common chemical found in e-cigarettes is ketene. When it enters the lungs after inhaled, this chemical causes damage to the cellular structure of lung tissue causing the cells to not function at maximum capacity and not absorb gasses as readily. This can cause shortness of breath which can lead to other health conditions such as tachycardia and respiratory failure. E-cigarette users who use devices that contain nicotine are exposed to its potentially harmful effects.^[91]the evidence is of poor quality.^[24]