Heart Attack And Smoking

What is a heart attack? 

A heart attack is a life-threatening medical emergency called a myocardial infarction (MI). A heart attack happens when the blood flow to the heart is blocked due to insufficient oxygen.

When you suspect someone is having a heart attack, you must call 999 (in the UK) and ask for an ambulance. The longer the person is left untreated by medical professionals, the bigger the chance their heart muscle will be damaged. A heart attack can often cause permanent damage and death if the blood flow is not restored quickly.

Symptoms of a heart attack 

The symptoms of a heart attack can be different for each individual. They can include any of the following:

  • Chest pain that gets worse
  • Severe pressure and squeezing in the middle of the chest that lasts for several minutes
  • Pain that spreads to the shoulders, neck, arms, or jaw
  • Dizziness or fainting
  • Sweating
  • Shortness of breath
  • Rapid, irregular heartbeat
  • An overwhelming feeling of anxiety, like a panic attack
  • Feeling sick (nausea)
  • Coughing or wheezing (high-pitched whistling sound made while breathing)

In many cases, the chest pain is severe, but some people only experience minor pain. Although chest pain is a widespread symptom of a heart attack in both people assigned male at birth (AMAB) and those assigned female at birth (AFAB), the latter more often also experience shortness of breath, feeling sick and back or jaw pain.

Why does smoking increase the risk of a heart attack?

Smoking contributes to chronically high blood pressure

Smoking is the most significant preventable cause of heart-related diseases. Approximately 70% of chronic obstructive pulmonary disease (COPD) cases (which cause airflow blockage and breathing-related problems) are heavy smokers. One of the ways smoking contributes to a higher risk of heart attack is by elevating blood pressure. High blood pressure, medically termed hypertension, damages the arteries due to the constant high pressure against the walls of the arteries. 

Smoking also stiffens the arteries, which causes the heart to work harder to move the blood around in the body.4

Nicotine, which is found in all tobacco products, has been shown to increase blood pressure by affecting the sympathetic nervous system (a network of nerves responsible for the ‘fight-or-flight’ response).5 As a result, smoking cigarettes and consuming other tobacco products increase the risk of heart attack by causing high blood pressure.

Doctors recommend that people with high blood pressure quit smoking to lower their risk of a heart attack.1

Smoking increases blood thickness 

Smoking directly affects the blood; it makes it thicker and stickier. When your blood is sticky, your heart has to work harder to pump the blood around your body, causing a higher risk of a heart attack.2

Studies have shown that blood thickness caused by smoking increases cardiovascular (heart and blood vessel-related) risk. They have also demonstrated that this risk can be reduced after three months of quitting smoking.2

Smoking can cause blood clots in the coronary arteries 

What is a blood clot?

When a blood vessel is injured, the blood coagulates or clots preventing excessive bleeding. Platelets (blood cells responsible for clotting) and the proteins in the blood plasma work together to stop bleeding. Normally, blood clots dissolve after the injury. However, in some situations, the clots don’t dissolve naturally or appear when there is no obvious sign of injury.

Blood clots can have several different symptoms, depending on where they are located in the body. If you suspect that you have one, you should get medical help immediately.

How does smoking cause blood clots?

Studies have shown that the blood platelets of smokers get activated 100 times more than the platelets of non-smokers.3 This causes an increase in blood clotting that can lead to deep vein thrombosis (DVT) by blocking one of the veins if it goes untreated.

Long-term blockage can have devastating consequences. A large clot can cause the lungs to collapse, resulting in heart failure.

10% of people with an untreated DVT develop severe pulmonary embolism (a clot blocking blood flow to the lungs), which can be life-threatening.

Tips on how to quit smoking 

Quitting smoking is one of the most beneficial actions that people can take to lower their risk for heart-related disease. By quitting smoking, you will be:

Quitting smoking also improves the survival chances of those who have already been diagnosed with coronary heart disease. It reduces the risk of another heart attack, premature death and death from heart disease.

Tips to help you quit

The NHS has several resources and tips to help you stop smoking. You can do some of these things to help you:

  • List your reasons for quitting; this will keep you motivated
  • Tell other people that you are stopping (accountability)
  • Have a plan for when you are tempted to smoke
  • Identify your triggers and try to avoid them
  • When you feel the urge to smoke, try to exercise instead
  • Join online and face-to-face groups for support and advice
  • Use stop smoking aids and treatments 

When to contact a doctor 

When a heart attack is suspected, you must immediately contact emergency services (abovementioned symptoms). In the United Kingdom, you must dial 999 to order an ambulance. If you are suffering symptoms of blood clots, you should dial 111 for further assistance. Symptoms of a blood clot:

  • Throbbing and cramping pain, swelling, redness in your leg or arm
  • Sudden shortness of breath and chest pain accompanied by cough or coughing up blood

It is vital to treat blood clots immediately, lest they become life-threatening.


Cigarette smoking harms the arteries, thickens the blood, raises blood pressure, and can cause potentially fatal blood clots. Research has demonstrated that quitting smoking improves health and reduces the risk of heart-related disorders.


  1. Saladini F, Benetti E, Fania C, Mos L, Casiglia E, Palatini P. Effects of smoking on central blood pressure and pressure amplification in hypertension of the young. Vascular Medicine. 2016 Jul 7;21(5):422–8.
  2. Shimada S, Hasegawa K, Wada H, Terashima S, Satoh-Asahara N, Yamakage H, et al. High Blood Viscosity Is Closely Associated With Cigarette Smoking and Markedly Reduced by Smoking Cessation. Circulation Journal [Internet]. 2011 [cited 2021 Mar 27];75(1):185–9.
  3. Tapson VF. The Role of Smoking in Coagulation and Thromboembolism in Chronic Obstructive Pulmonary Disease. Proceedings of the American Thoracic Society. 2005 Apr 1;2(1):71–7.
  4. Doonan RJ, Hausvater A, Scallan C, Mikhailidis DP, Pilote L, Daskalopoulou SS. The effect of smoking on arterial stiffness. Hypertens Res [Internet]. 2010 [cited 2023 Mar 6]; 33(5):398–410.
  5. Lee M-S, Rees VW, Koutrakis P, Wolfson JM, Son Y-S, Lawrence J, et al. Cardiac Autonomic Effects of Secondhand Exposure to Nicotine from Electronic Cigarettes. Environ Epidemiol [Internet]. 2019 [cited 2023 Mar 6]; 3(1):e033.
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