What Happens to Your Blood Pressure When You Smoke

Over the short- and long-term, smoking cigarettes can raise your blood pressure and increase your risk of hypertension (high blood pressure). In contrast, quitting cigarettes has an almost immediate beneficial effect on blood pressure, irrespective of how long or much you have smoked.

1. Chemicals in Tobacco Smoke Cause Blood Pressure to Rise

Blood pressure effects from tobacco smoke include:

• Acute effects: Even with the first puff, people experience a sudden (acute) rise in blood pressure. Smoking one cigarette can cause blood pressure to spike by as much as 20 millimeters of mercury (mmHg) for up to 30 minutes.
• Over time: Smoking regularly will almost inevitably lead to sustained (chronic) elevations, known as hypertension.

When you smoke tobacco, you expose your body to over 7,000 chemicals that can affect your circulatory system and blood pressure. Several contribute to this:

• Nicotine: This highly addictive chemical acts directly on the nervous system. It induces feelings of pleasure and triggers the release of the hormone norepinephrine, which causes blood vessels to narrow (vasoconstriction) and blood pressure to rise.
• Carbon monoxide: The burning of tobacco releases carbon monoxide gas into your lungs and bloodstream. These molecules bind strongly to red blood cells, causing blood oxygen levels to drop as oxygen molecules are displaced. To compensate, the heart will start to beat faster, leading to increased blood pressure.
• Oxidative stress: Smoking releases substances (such as hydrogen peroxide, quinones, cadmium, and nickel) that create an imbalance between harmful free radicals and helpful antioxidants, called oxidative stress. Increased free radical levels can contribute to hypertension by damaging blood vessels, leading to hardening and narrowing.

2. Your Risk Rises the Longer and More You Smoke

Studies have shown that cigarette smoking, independent of all other risk factors, increases the risk of hypertension by as much as 30%. The duration and amount you’ve smoked also factor in.

This is evidenced by a 2020 study of Hispanic adults in which the risk of hypertension among current smokers increased in tandem with their “pack-years” of smoking (calculated by multiplying the number of packs of cigarettes smoked per day by the number of years smoked).

The six-year study, involving over 7,000 adults, found that the “tipping point” for hypertension occurred after 5 pack-years, raising the risk by over 30%.

Five pack-years can mean that you smoke one pack (20 cigarettes) per day for 5 years, a half a pack (10 cigarettes) per day for 10 years, or five cigarettes per day for 20 years.

3. The Rise in Blood Pressure Can Lead to Serious Cardiovascular Conditions

Over the long term, smoking may lead to sustained elevations in blood pressure due to vascular damage and the onset of atherosclerosis (hardening of the arteries). When blood pressure readings are consistently 130/80 mmHg or higher, a person is said to have hypertension.

Smoking’s effects are concerning, as it can independently raise the systolic blood pressure (the upper blood pressure reading) by an average of 6 mmHg compared to non-smokers.

Such an increase may meet the diagnostic definition of hypertension. It may also increase a person’s risk of cardiovascular disease (CVD). According to a 2020 study in JAMA Cardiology, every 10 mmHg increase in systolic pressure increases the risk of CVD by 53%.

Hypertension significantly increases the risk of heart disease and stroke, the leading causes of death in the United States. Smoking, in turn, is the leading preventable cause of death.

4. Quitting Cigarettes Can Help

No matter how long or how much you have smoked, quitting can significantly reduce the risk of hypertension and its complications. The benefits can be immediate.

According to the American Heart Association:

• Within 20 minutes of quitting, your blood pressure drops from nicotine-induced highs.
• After several days, carbon monoxide levels in your blood return to normal.
• After two weeks, your circulation and lung function start to improve.
• Within 12 months, clearer and deeper breathing gradually returns.
• After 3 to 6 years, the risk of heart disease is cut in half.
• After 5 to 10 years, the risk of oral cancer is reduced by 50%.
• After 10 years, the risk of lung cancer also drops by half.
• After 15 years, the risk of heart disease is similar to that of a non-smoker.

Studies have shown that quitting cigarettes can reduce your systolic blood pressure by as much as 8 mmHg and diastolic (lower) blood pressure by as much as 4 mmHg after 12 weeks.