How long is nicotine in your system

Nicotine lasts in your bloodstream for one to three days, and cotinine can be detected in your blood for up to 10 days. Nicotine in your blood can be detected using tests that are qualitative (whether nicotine is present) and quantitative (how much nicotine is present).

Most of the nicotine leaves your blood in a few hours, but some amounts can remain for up to three days. Nicotine use can also be detected for much longer: Cotinine, a chemical formed when nicotine is being broken down in the body, is what lab technicians look for when testing if there’s nicotine in the blood.

Yes, your doctor can tell if you smoke occasionally by looking at medical tests that can detect nicotine in your blood, saliva, urine and hair. When you smoke or get exposed to secondhand smoke, the nicotine you inhale gets absorbed into your blood.

If you use nicotine replacement medicine , such as gum or a patch, the cotinine test will not give an accurate result. Breathing in secondhand smoke can also affect the result.

After two weeks: your circulation and lung function begin to improve. After one to nine months: clear and deeper breathing gradually returns; you have less coughing and shortness of breath; you regain the ability to cough productively instead of hacking, which cleans your lungs and reduce your risk of infection.