with over 7,000 chemicals released each time you light a cigarette it's no surprise that smoking is one of the leading causes of preventable deaths worldwide but with 1.3 billion people actively smoking what actually happens when you stop smoking within the first 20 minutes of quitting your blood pressure and heart rate return to normal this is because the nicotine in cigarettes released epinephrine and norepinephrine which increased your heart rate and narrowed blood vessels these effects also caused smokers extremities to feel colder but by now your hands and feet have returned to their normal temperature 2 hours in and the nicotine cravings begin causing moodiness drowsiness tense feelings and even difficulty sleeping because nicotine also releases more dopamine than normal these are expected physiological responses to the decrease in its release eight hours after quitting and the inhaled carbon monoxide clears allowing oxygen levels in the bloodstream to return to normal carbon monoxide and oxygen compete to bind to hemoglobin in your blood which stretches the circulatory system so as it clears there's more room for oxygen however for long-term smokers this carbon monoxide exposure causes red blood cells to increase in size making the blood thicker and causing higher blood pressure and increased chances of developing blood clot surprisingly 24 hours after quitting coughing will actually increase which is your body's way of clearing out all the toxins from the lungs additionally at this point the risk of developing various coronary artery diseases decreases all within 24 hours after 48 hours when nicotine and its metabolites are completely eliminated from your body damaged nerve endings begin to regrow the tar and other chemicals and cigarettes leave fewer taste buds that are flatter with less blood vessels they now begin to regain their sensitivity making food tastes better although chronic smokers may often have irreversibly damaged taste blood at the 72-hour mark nicotine withdrawal peaks with headaches nausea and cramps as well as emotional symptoms like anxiety and depression these symptoms can be seen by most addictive substances cluding caffeine but after this period the worst is officially over after one month the risk of developing type 2 diabetes cancer and cardiovascular diseases has already decreased in three to nine months the damage Celia and the lungs are almost fully repaired which are hairlike structures that help sweep away dust and debris and as a result symptoms such as coughing and shortness of breath are almost completely eliminated and around one year the risk of developing heart disease as a direct result of at the Roma formation which are deposits of fatty material or scar tissue from deteriorating arterial walls decreases by almost one-half in 10 years the chance of developing lung cancer decreases to half of someone who did not quit smoking and in 15 years time the risk of heart attack decreases to the same as someone who has never smoked their entire life of course this guideline is not definitive and the average amount you smoke per day or year will play a role in how well your body recovers unfortunately there will always be some irreversible damage to the lungs and increased susceptibility to developing various lung diseases and while quitting may be difficult the benefits greatly outweigh the initial withdrawal ultimately the best way to prevent this from happening is to not begin smoking at all need some extra motivation check out our videos to your lazy people which might give you the boost you need to kick your habit or focus on other goals you're hoping to accomplish ask us your burning questions in the comments or on social media and subscribe for more weekly science videos every Thursday