2 days without smoking: what happens to your body

The NHS says that by 48 hours after your last cigarette, carbon monoxide in your blood has dropped to the level of someone who doesn't smoke. That means more of your red blood cells are carrying oxygen again instead of carbon monoxide.

Your lungs also start to clear out mucus around this point (NHS). Some people notice more coughing or phlegm in the first days. The NHS describes this as a short-term process while your airways clear.

Taste and smell begin to improve at 48 hours, according to the NHS, and it notes you may feel hungrier from this point as food starts tasting better.

Withdrawal can start within a few hours of your last cigarette and is strongest in the first week, especially the first 3 days (NHS). Day 2 sits right in that window. Your brain is used to regular nicotine and is adjusting to having none.

A research review of tobacco withdrawal found that the core symptoms peak within the first week and last 2–4 weeks. Those symptoms are anger, anxiety, low mood, difficulty concentrating, impatience, trouble sleeping and restlessness. They are temporary, even when day 2 makes them feel permanent.

Plan for the cravings, not just the day. Quit (Australia) suggests the 4 Ds: delay acting on the craving for about 5 minutes, take slow deep breaths, do something else, and drink water. The NHS also suggests keeping your mouth busy with carrot sticks, celery or sugar-free gum, and avoiding triggers such as coffee breaks with smokers for the first 28 days.

If you are not using a stop smoking medicine yet, it is not too late to start. The CDC says FDA-approved quit medicines can double your chance of quitting for good. A pharmacist, GP or quitline can help: your local NHS Stop Smoking Service (UK), Quitline 13 7848 (Australia), or 1-800-QUIT-NOW (US). Withdrawal is unpleasant but not dangerous. Chest pain, fainting or severe breathlessness are not normal withdrawal and need urgent care.