What happens when you
stop smoking?
The first few hours are the sharpest. Nicotine is leaving your blood and the restlessness you feel is that drop, not damage.
This is the same timeline the app uses for smoking, shisha and chewing tobacco.
The timeline
-
20 minutes
Heart rate settles
Heart rate and blood pressure begin to return to normal.
Over the next few hours the nicotine level in your blood keeps falling. Restlessness is the drop, not damage.
NHS
-
8 hours
Oxygen recovering
Nicotine and carbon monoxide in the blood halve; oxygen levels rise.
Through the first day oxygen keeps climbing back towards normal. Expect the strongest cravings of the whole process in this stretch.
NHS
-
1 day
Carbon monoxide gone
Carbon monoxide is cleared and the lungs start shifting mucus.
The lungs begin clearing out. A cough that appears now is usually them working, not getting worse.
NHS
-
2 days
Taste and smell return
No nicotine left in the body. Taste and smell noticeably sharper.
Irritability and poor concentration tend to peak across days two and three. This is the hardest stretch and it is short.
NHS
-
3 days
Breathing easier
Bronchial tubes relax, energy levels rise.
From here the physical withdrawal fades week by week and what is left is habit rather than chemistry.
NHS
-
2 weeks
Circulation improves
Walking and exercise start to feel easier.
Circulation keeps improving over the coming weeks. Exercise gets steadily less unpleasant.
NHS
-
4 weeks
Skin improves
Skin appearance and colour improve as blood flow recovers.
Lung function climbs quietly through the next couple of months. Most people notice stairs before they notice anything else.
NHS
-
3 months
Lung function up
Lung function can be up to 10% better than when you smoked.
The cilia in your airways regrow across the next few months, which is what eventually stops the cough.
NHS
-
9 months
Lungs clearing
Coughing and breathlessness decline as the cilia recover.
Coming up on a year, the cardiovascular repair is the part doing the real work now.
NHS
-
1 year
Heart risk halved
Risk of heart disease is around half that of a smoker.
Risk keeps falling year on year from here. Nothing you have to do - it is simply time now.
NHS
-
5 years
Stroke risk falls
Stroke risk moves towards that of someone who never smoked.
The long tail. Lung cancer risk is the slowest of the risks to come down, and it is still coming down.
CDC
-
10 years
Lung cancer risk halved
Risk of lung cancer is around half that of a smoker.
Heading towards the fifteen-year mark, where the heart attack risk finishes catching up with a never-smoker.
CDC
-
15 years
Heart attack risk normal
Risk of heart attack matches someone who never smoked.
CDC
And the other half of it
At the app's default of £16 a day, smoking costs about £5,844 a year. Work out your own figure — it takes a second and nothing is sent anywhere.
Why it happens
Two different clocks
Nicotine has a half-life of about two hours, so it is essentially gone from the blood within a day - which is why the physical craving is sharpest on day one and largely finished within three. Carbon monoxide runs on its own clock: it binds to haemoglobin roughly 200 times more readily than oxygen does, and that bond takes three to five hours to halve. Clearing it is why oxygen delivery improves so quickly.
Why cravings outlast the nicotine
A smoker's brain grows extra nicotinic acetylcholine receptors - roughly double the density of a non-smoker's. They do not disappear when the nicotine does. Numbers come back down over weeks to months, which is why the chemistry is finished long before the wanting is.
The lungs, which are the slow part
Cilia - the hair-like sweepers lining the airways - are paralysed by smoke and largely absent in long-term smokers. They regrow over months, and the cough that appears in the first weeks is usually them starting to work again rather than anything getting worse. Lung function improves for up to nine months; cardiovascular risk keeps falling for fifteen years.
Where this comes from
General guidance, not medical advice. Talk to a doctor before making changes if you have any health concerns.
Days Strong counts the days you did not, shows you where you are on this timeline, and turns the money into something you actually want. No account, and it all stays on your phone.