In the first 24 hours after your last cigarette, your heart rate starts to fall and carbon monoxide in your blood begins to drop. You may also have cravings, feel restless, or find familiar routines suddenly difficult. Here is what to expect and what to do tonight.
In your body
At about 20 minutes, your heart rate starts to fall.
Between 8 and 12 hours, carbon monoxide in your blood drops. Carbon monoxide from smoke reduces how much oxygen your blood can carry. You may not feel this change on the first day.
Around 24 hours, nicotine in your blood has fallen to zero if you are not using other nicotine products, including nicotine replacement therapy, according to the Centers for Disease Control and Prevention (CDC) timeline. Heart and lung benefits continue to develop over the months and years ahead.
In your head
You may notice:
- Cravings tied to coffee, meals, breaks, or other smoking routines.
- Restlessness, irritability, or trouble concentrating.
- Slightly worse sleep on day one or two for some people.
- Hunger or a desire to put something in your mouth (gum and water are useful).
Cravings often ease after a few minutes, but they can return. Keep two or three actions ready: drink water, walk for two minutes, breathe slowly, or change rooms. If one craving lasts longer than you expected, keep delaying and ask for support.
What to do tonight
Make the next craving harder to act on:
- Throw the open pack away. Not in a kitchen drawer “just in case.” Out.
- Record the time of your last cigarette. A timer or simple note can show how far you have come.
- Have a craving plan written down. One sentence is enough: “When a craving hits, I drink water and walk for two minutes.”
If a craving arrives tonight, use the plan you wrote instead of deciding what to do while the urge is strongest. For more options, see the nicotine cravings guide.
This content is informational and does not replace medical advice. Get urgent medical help for chest pain, severe shortness of breath, or thoughts of self-harm. If panic or low mood persists, speak with a healthcare professional.
Sources checked
- CDC, Benefits of Quitting Smoking: early heart-rate and blood-nicotine changes, and longer-term health benefits.
- NHS Better Health, Understanding the true impact of smoking: early pulse and carbon-monoxide changes.
- Smokefree.gov, Managing Nicotine Withdrawal: common early withdrawal symptoms.
- Hughes JR, Hatsukami D, “Signs and symptoms of tobacco withdrawal,” Archives of General Psychiatry (1986): craving, irritability, anxiety, trouble concentrating, restlessness, insomnia, and hunger increased during the first four days without smoking.
- Jaehne A et al., “Sleep changes in smokers before, during and 3 months after nicotine withdrawal,” Addiction Biology (2015): small sleep-lab study that found more night-time awakenings and time awake 24 to 36 hours after stopping.
Frequently asked questions
-
Is it normal to feel restless or irritable on the first day without cigarettes?
- Yes, it can be. Restlessness, irritability, trouble concentrating, and hunger are common early withdrawal symptoms. Get urgent medical help for chest pain, severe shortness of breath, or thoughts of self-harm.
-
When does nicotine leave your blood after quitting?
- According to the CDC timeline, nicotine in your blood falls to zero around 24 hours after your last cigarette. That timing does not apply if you use other nicotine products, including nicotine replacement therapy.
-
Will I feel healthier after the first day?
- Maybe not yet. Your heart rate starts to fall and carbon monoxide in your blood drops within the first day, but you may not notice these changes. Heart and lung benefits keep developing over the months and years ahead.
-
How long does a craving last on day one?
- Cravings often ease after a few minutes, but they can come back during the day. Keep two or three actions ready, such as drinking water, walking for two minutes, or changing rooms, so you can wait each one out.