Who gets a stroke?
Anyone can get a stroke but there are several risk factors that have been identified that increase the risk of having a stroke. Some of these can be modified and some cannot:
Risk factors that can be modified:
High blood pressure
Having high blood pressure definitely confers an increased risk of having a stroke. It can lead to a build-up of plaque which can eventually block off arteries and cause a stroke. It is a good idea to have your blood pressure checked every 3-6 months. There are no symptoms of having high blood pressure and unless it is checked there is really no way of knowing that the blood pressure is high. It is a controllable risk factor- both through medication and lifestyle. The most important thing is to identify that you have it and once you are aware of it you should keep a close eye on it. Ask your doctor what your blood pressure reading is and what it means.
Having high cholesterol can also increase your risk of having a stroke. Cholesterol is a waxy substance that is found in the fats (or lipids) in the blood. It is carried with proteins- together referred to as lipoproteins. You may have heard of the terms “good” cholesterol and “bad” cholesterol. The other name for good cholesterol is high density lipoprotein or HDL. This is considered a good cholesterol as it carries cholesterol away from the cells and back to the liver where it is broken down or passed out of the body as a waste product. The other name for bad cholesterol is low density lipoprotein or LDL. This is considered a bad cholesterol because it carries cholesterol to the cells that need it but if there is too much cholesterol it then builds up and can clog arteries which may lead to things like heart attacks and stroke. Inactivity, obesity and an unhealthy diet can all contribute to having a high amount of bad cholesterol and low amount of good cholesterol. Lifestyle changes are the first ways to tackle a high cholesterol. Avoiding foods that are high in saturated and trans fats such as red meat, butter, cheeses as examples may help reduce cholesterol levels. Substituting with monounsaturated fats- such as those found in avocado, walnuts and almonds as examples- would be a positive step forward. Also, increasing the amount of fresh fruit and vegetables in your diet would be a good way of avoiding the cholesterol rich foods. Sometimes having high cholesterol can be an inherited condition. In a lot of people there may be a combination of poor lifestyle factors and an inherited component. In this scenario modification of lifestyle will again be the first step towards reducing your risk of stroke. High cholesterol is something that you will not have any symptoms of so it is worth checking it once or twice a year with your GP after the age of 40 or earlier if there is a family history. If you are overweight, are a smoker, have diabetes or high blood pressure you should also consider having your cholesterol levels checked. Smoking alone can actually increase your bad cholesterol levels as it stops the good cholesterol from bringing the cholesterol to the liver so that it can be broken down. In some people diet and lifestyle changes alone may not be enough to reduce cholesterol and a medication may be added to help. The most commonly used medication for reducing cholesterol is called a statin. It works by blocking a substance in your liver that is needed to make cholesterol. This causes your liver to remove cholesterol from your blood. If you are on a statin medication you may need to have your liver function monitored to see the effect they are having on your liver function. There are several other medications that can be used if for some reason you cannot tolerate a statin medication. These require an individualised approach.
Diabetes is a condition whereby your blood sugar levels are too high. This can be a result of your body either not producing insulin (Type I diabetes- common in children and adolescents) or not producing enough insulin or the cells have become resistant to the effects of insulin (Type II diabetes- more common in older especially overweight people). Without insulin or being resistant to insulin means your body cannot regulate the amount of sugar in your blood. The excessive amounts of glucose eventually lead to fatty deposits in blood vessels and therefore an increased risk of stroke. Having diabetes can almost double your risk of getting a stroke. If you have diabetes you should know what your average sugar is. You should also know what your HbA1C is- this is a blood test that gives an average of your blood sugar control over the previous 2-3 months. More information can be found at www.stroke.org/diabetes.
Being over-weight increases the risk of stroke. The term obesity is used to describe the health condition of anyone significantly above his or her healthy ideal weight. The body mass index (BMI) is used to evaluate for obesity. There are online calculators to help you understand what yours is. As a guideline 18.5- 25 is normal. < 18.5 is underweight, between 25- 29.9 is overweight and >30 is considered obese. You should calculate your own BMI. If it falls in to the over-weight or obese category you should see what changes you can make to try and get it in to the normal range. Being obese puts extra pressure on the heart and blood vessels leading to a greater demand on the heart to pump blood around the body. Being overweight also increases the chance of you developing diabetes and high blood pressure which both independently increase stroke risk. A healthy lifestyle plan with dietary modifications can significantly reduce this risk factor for stroke. Educate yourself- know how many calories you should eat every day. To successfully and healthily lose weight and keep it off most people need to subtract around 500 calories from their daily diet. There are a lot of helpful tips and information on www.strokeassociation.org.
Smoking significantly increases the risk of having a stroke. The nicotine and carbon monoxide in cigarette smoke damage the cardiovascular system and significantly increase the risk of a stroke. If you are a smoker and give up, your risk of heart disease and stroke begins to drop. In the year after you quit smoking the excess risk of heart disease and stroke decreases by 50%. After 15 years your risk of having a stroke will go back towards the same as someone who never smoked. So no matter how long you have smoked for it is always still worthwhile giving up.
A sedentary lifestyle without much exercise or physical activity will also lead to a higher risk of stroke. The Irish Heart Foundation recommends 30 minutes of light to moderate exercise daily to reduce the risk of heart attacks and the same principle applies to stroke. Physical activity can help to reduce bad cholesterol by increasing the amount of good cholesterol. Also, physical activity will reduce the chances of you becoming obese and can lower the chance of you developing diabetes. If you are told by your doctor that you have “pre-diabetes” as in your blood sugar is not normal but is not quite in the range of having diabetes physical activity at the levels recommended by the American Heart Association and Irish Heart Foundation can reverse this state of “pre-diabetes”. This is especially relevant if you have already had a stroke or mini stroke as a means of preventing another one.
Stress can have a huge impact on our lives. Some stress can be good for us in terms of motivation to get a project finished or some other short term achievable goal. It is less useful when it becomes chronic. It can lead to several poor lifestyle habits such as poor sleep, excess alcohol intake, comfort eating and then feeling too tired to exercise. When stress leads to these outcomes it becomes very detrimental to overall health.
Excessive alcohol intake
>1 drink/day for women and >2 drinks/day for men is associated with an increased risk of stroke. One reason for this is that chronic excessive alcohol intake leads to high blood pressure.
Heart rhythm disorders
The most common heart rhythm disorder that is associated with an increased risk of stroke is atrial fibrillation. What this essentially means is that your heart is not beating regularly as it should do and the result of this is that blood can pool in the heart and because it is not supposed to do this it has a tendency to clot. The clot can then break off and travel in the vessels and lead to a stroke. Excessive alcohol intake and uncontrolled high blood pressure are both risk factors for developing an irregular heart rhythm. This is a very treatable condition once it is diagnosed. A symptom of this might be the feeling of your heart fluttering in your chest although not everyone will have symptoms. The best thing you can do is avoid the risk factors such as excessive alcohol intake and high blood pressure.
Having sleep apnoea increases the risk of stroke. Sleep apnoea is a condition whereby during sleep your airways close off depriving you of oxygen which then causes you to wake up and start breathing again. The result of this is a very poor quality of sleep. Also, with multiple awakenings during the night you are at a higher chance of developing high blood pressure. When we go to sleep there is a natural dip in blood pressure which is healthy but if you keep waking up during the night then you lose this restorative measure. Also, if you have not slept well you are more likely to avoid physical activity and eat more unhealthily. Sleep apnoea is an easily treated condition once identified. People who are obese are at greater risk of developing this as there is simply more pressure placed on the airways. It is usually identified by the bed partner as excessive snoring. However, you may notice excessive daytime sleepiness or morning time headaches which can be signs that you do have sleep apnoea.
Risk factors that cannot be modified:
Stroke occurs more in men at younger ages. However, more women die of stroke than men each year mainly because women live longer than men and the stroke risk increases with age.
The older we are the higher the chance of having a stroke. After the age of 55 stroke risk doubles for every decade a person is alive.
Race and ethnicity
People of African descent have a higher risk of stroke partially because they are more susceptible to high blood pressure, diabetes and obesity.
If there is a family history of stroke at a young age you will have a higher risk of stroke. It is worth delving in to the detail of the family history to see if there is a genetic predisposition or clotting disorders that contribute to this increased risk.
Having already had a stroke or TIA confers an increased risk of a recurrent stroke and extra emphasis should be placed upon the risk factors that can be modified (as above).