Stroke And Smoking

What is a stroke?

The brain depends on oxygen to function properly and an uninterrupted supply of this is, therefore, crucial for optimal brain function. Brain cells begin to die within minutes if their oxygen supply is interrupted.

In a stroke, parts of the brain lose their oxygen supply and die off. The severity of the stroke depends on the area(s) of the brain involved, and the amount of brain tissue involved (size of the affected area(s)).

There are two main types of strokes:

• Ischaemic stroke - is caused by a blood clot in one of the blood vessels supplying oxygen-rich blood to the brain. This type of stroke is the most common, with a prevalence of 80%. 
• Haemorrhagic stroke - results from rupture (bursting) of one of the blood vessels in the brain. This type of stroke is less frequent than an ischemic stroke and accounts for about 20% of all strokes.

Both types of stroke result in an interruption in blood supply to part(s) of the brain.

The brain controls various body functions like movement, speech, and vision. Stroke symptoms, therefore, vary depending on the affected brain area(s). For example, if the brain area that loses its oxygen supply is the part that affects speech, then a person is likely to experience speech difficulties.

Strokes are quite common, with one in four people being at risk of developing a stroke; they are the second leading cause of death worldwide.¹

Smoking is one of the main risk factors for a stroke

Certain risk factors for stroke have been identified such as high blood pressure and diabetes. Smoking is also a major risk factor for stroke with smokers being about three times more likely to have a stroke than people who have never smoked. The risk is directly proportional to the number of cigarettes smoked and begins to decline soon after smoking is stopped.^2,3 

The link between smoking and stroke is so strong that even second-hand smoke has been found to almost double the chances of stroke in repeatedly exposed people.⁴ Smoking leads to stroke by causing harmful changes to both the blood vessels in the brain and the blood that flows within them.

What does smoking do to the blood vessels in the brain?

There is a stronger association between smoking and ischaemic stroke than there is with haemorrhagic stroke. While some studies have found links between smoking and haemorrhagic stroke, others have found no significant association.⁵

A group of cells in the blood, called platelets, are responsible for the blood clotting and were found to be more activated in smokers than in non-smokers. This means the platelets in smokers have a greater tendency to clump together and form blood clots. If these clots travel to the blood vessels in the brain, they could lead to a stroke by blocking the vessels.⁶

Cigarette smoke contains free radicals which are harmful to the lining of the blood vessels. In the brain, these free radicals cause injury to the cells that line the inner portion of the blood vessels. This injury triggers a cascade of events that results in the formation of a clot that narrows and could ultimately block affected vessels. Parts of the brain that are supplied by this blocked vessel are starved of oxygen-rich blood, and die off, leading to stroke symptoms.⁶

Smoking increases the risk of high blood pressure. Blood vessels are usually elastic; they are able to expand and contract to accommodate changes in blood volume. However, smoking hardens the walls of these vessels, making them stiff. They become inelastic, leading to an increase in the pressure within them - high blood pressure.⁷ 

This elevated blood pressure is an independent risk factor for stroke and is thus another way in which smoking predisposes the condition.⁷

Tips for quitting smoking

• Write down your motivation for quitting and keep referring to it.
• Write down your smoking triggers and avoid them - particular places or settings such as bars or parties which may bring on a strong urge to smoke. Stay away from them until you feel you have gone far enough in your quitting journey to be able to resist the urge to smoke.
• Throw out all smoking paraphernalia - cigarettes, lighters, and anything that could bring on a strong urge to smoke.
• Set a quit date and inform everyone of your plans - your family, friends, and co-workers can help keep you accountable if you let them know about your plan to quit.
• Speak to your healthcare provider about the appropriate stop-smoking aids for you - nicotine gum and patches, and prescription drugs like bupropion and varenicline.
• Join a support group/find a support buddy - you can get this from your local stop-smoking service.
• Keep physically active - this can help distract you from cravings.

When to contact a doctor

The symptoms of stroke often develop suddenly. Some of them include:

• Weakness or numbness of the face, arms, and/or legs - these are usually one-sided. 
• Drooping of one side of the face.
• Speech difficulties - including nonsensical speech and difficulty speaking.
• Difficulty walking from dizziness, poor balance, or leg weakness.
• Difficulty seeing with one or both eyes.
• Headache which may be associated with vomiting.

Seek medical attention immediately if you or anyone you know begin to experience any of the above symptoms.

Conclusion

A stroke is a debilitating condition which could lead to death, lifelong disability, and exorbitant healthcare costs. Smoking is a well-established risk factor for stroke and quitting smoking has been shown to decrease this risk.

Speak to your healthcare provider today about useful resources to help you quit smoking, as quitting begins to lower your stroke risk almost immediately.