what will happen if i stop smoking now?

Within …

# 20 minutes
Your blood pressure, pulse rate, and the temperature of your hands and feet will all return to normal.
# 8 hours
Remaining nicotine in your bloodstream will have fallen to 6.25% of normal peak daily levels, a 93.25% reduction.
# 12 hours
Your blood oxygen level will have increased to normal and carbon monoxide levels will have dropped to normal.
# 24 hours
Anxieties peak and within two weeks should return to near pre-cessation levels.
# 48 hours
Damaged nerve endings have started to regrow and your sense of smell and taste are beginning to return to normal. Cessation anger and irritability peaks.
# 72 hours
Your entire body will test 100% nicotine-free and over 90% of all nicotine metabolites (the chemicals it breaks down into) will now have passed from your body via your urine. Symptoms of chemical withdrawal have peaked in intensity, including restlessness. The number of cue induced crave episodes will peak for the “average” ex-user. Lung bronchial tubes leading to air sacs (alveoli) are beginning to relax in recovering smokers. Breathing is becoming easier and the lungs functional abilities are starting to increase.
# 5 – 8 days
The “average” ex-smoker will encounter an “average” of three cue induced crave episodes per day. Although we may not be “average” and although serious cessation time distortion can make minutes feel like hours, it is unlikely that any single episode will last longer than 3 minutes. Keep a clock handy and time them.
# 10 days
10 days – The “average ex-user is down to encountering less than two crave episodes per day, each less than 3 minutes.
# 10 days to 2 weeks
Recovery has likely progressed to the point where your addiction is no longer doing the talking. Blood circulation in our gums and teeth are now similar to that of a non-user.
# 2 to 4 weeks
Cessation related anger, anxiety, difficulty concentrating, impatience, insomnia, restlessness and depression have ended. If still experiencing any of these symptoms get seen and evaluated by your physician.
# 21 days
Brain acetylcholine receptor counts up-regulated in response to nicotine’s presence have now down-regulated and receptor binding has returned to levels seen in the brains of non-smokers.
# 2 weeks to 3 months
Your heart attack risk has started to drop. Your lung function is beginning to improve.
# 3 weeks to 3 months
Your circulation has substantially improved. Walking has become easier. Your chronic cough, if any, has likely disappeared.
# 1 to 9 months
Any smoking related sinus congestion, fatigue or shortness of breath have decreased. Cilia have regrown in your lungs thereby increasing their ability to handle mucus, keep your lungs clean, and reduce infections. Your body’s overall energy has increased.
# 1 year
Your excess risk of coronary heart disease has dropped to less than half that of a smoker.
# 5 to 15 years
Your risk of stroke has declined to that of a non-smoker.
# 10 years
Your risk of death from lung cancer has declined by almost half if you were an average smoker (one pack per day). Your risk of cancer of the mouth, throat and esophagus has now decreased.
# 15 years
Your risk of coronary heart disease is now that of a person who has never smoked.