Some people report feeling dizzy or lightheaded when they quit smoking. There are a few things that can contribute to these symptoms, and some may be related to nicotine withdrawal. You should discuss any ongoing dizziness with your doctor as it could be a sign of an underlying condition rather than being related to your smoking cessation.
Quit Aids and Dizziness
Some quit aids may cause dizziness for users. The nicotine patch, a form of nicotine replacement therapy (NRT) that looks like a tan or clear bandage, lists dizziness as a common side effect. However, all NRTs contain nicotine, and a nicotine overdose can cause dizziness.1
If you're using nicotine replacement therapy to help you stop smoking, it is important that you follow the manufacturer's directions for use carefully. Be sure to match the initial dosage level to how much you were smoking. You don't want to take in more nicotine than you were used to getting as a smoker. Also, be sure to wean off of NRTs in the time suggested, as there is a risk of dependence.2
Zyban (bupropion), a non-nicotine quit aid, has a side effect of dizziness for some people. Zyban was originally marketed and prescribed under the name Wellbutrin as an anti-depressant. Then it was discovered that smokers using it lost interest in smoking.3
Nicotine is a stimulant, meaning it speeds up some of the body's functions. When you smoke, nicotine is absorbed into the bloodstream through the lining of the lungs. It reaches the brain within seven to 10 seconds. Once there, it causes a chemical reaction that releases adrenaline, the "fight or flight" hormone. Adrenaline speeds the heart up, constricts blood vessels, and raises blood pressure.
Additionally, carbon monoxide from cigarette smoke reduces the amount of oxygen in the blood. Both factors work to diminish blood flow (and oxygen) to the brain.5
When you stop smoking, nicotine is no longer triggering adrenaline to constrict blood flow. In the absence of inhaled carbon monoxide, there is more oxygen in the blood. Some people believe this could cause dizziness for the newly ex-smoker. However, there have been no conclusive studies that show this to be the case.
How Nicotine Affects the Body
Nicotine and Blood Sugar
In addition to the stimulant effects, nicotine also slows the release of insulin from the pancreas. Insulin is a hormone that removes excess sugar from the blood. It is instrumental in helping the body keep blood sugar in balance. This imbalance leaves smokers slightly hyperglycemic, with more sugar in their blood than they should have.6
Hunger is a symptom of nicotine withdrawal and of hypoglycemia (low blood sugar). Moderate hypoglycemia can produce feelings of dizziness. Research has not shown a direct correlation between nicotine and low blood sugar when quitting tobacco.