Hypertension

Definition:    

Blood pressure is a measurement of the force of blood flow inside your arteries. Your blood pressure is stated as two figures, e.g. 120/80mmHg (millimetres of mercury). The first figure is known as the systolic pressure and relates to the pressure as the heart contracts and pushes blood out to the body. The second figure is the diastolic pressure and is when the heart relaxes again to fill up with blood.

Hypertension is not a discrete condition—increased level of pressure, either systolic or diastolic, increase the risk of heart disease (cardiovascular disease) and stroke to such a degree that action is necessary. The levels of maximum accepted pressure in the UK are 140 systolic and 90 diastolic but ideally it needs to be below this. When a doctor says “you have high blood pressure” they mean that your level of risk is such that action is needed to lower your risk of developing heart disease or having a stroke. This might include taking medication to lower your blood pressure, the benefits of which far   outweigh the possible, usually minor, side effects.

Cause for scope and prevention:

Modifiable lifestyle factors such as lack of activity, increased body weight, and a poor diet high in fat and salt are considered to contribute to hypertension. Genetic influences may also play a part in the development of the condition.

Diagnosis:

A diagnosis and classification of hypertension occurs when an elevated blood pressure is taken at rest, often 2 separate readings are needed to confirm the diagnosis.

There are different stages of hypertension depending on blood pressure.

Classification                      Systolic(mmHg)                     Diastolic (mmHg)

 Normal                                         < 120                                        And <80

 Prehypertension                        120-139                                   Or 80-89

 Stage 1 hypertension               140-159                                   Or 90-99

Stage 2   hypertension                >160                                       Or >100

Standard medical therapy:

Most people with prehypertension should be managed mainly with lifestyle interventions such as exercise therapy and dietary modification. 

People with stage 1 or stage 2 hypertension often require a combination of the lifestyle interventions described above in conjunction with blood pressure medication. There are many different blood pressure medication types and those with stage 2 hypertension will often require 2 or more medications.  

Benefits of exercise therapy:

Regular exercise will reduce your blood pressure and is therefore essential for those with hypertension. On average, exercise reduces blood pressure by about 6-7 mmHg. Studies have shown that, if systolic blood pressure is reduced by 5 mmHg, deaths from strokes decrease by 14% and deaths from coronary heart disease (i.e. blocking of the blood vessels that supply the heart) decrease by 9%. Decreasing systolic pressure by 20mmHg halves the risk of cardiovascular mortality.

Exercise has been shown to be as effective as some blood pressure medications and should be the first treatment recommended to lower blood pressure, especially for those with prehypertension and stage 1 hypertension.

The focus of an exercise for those with   hypertension should be a graduated aerobic program at a low to moderate intensity. For most people the aim should be to build up to 30 minutes of moderate intensity exercise, 5 days a week over a period of around 12 weeks.

Exercises such as brisk walking, cycling, gym-based exercise or home-based aerobics are ideal. Depending on the current fitness level and symptoms, it may be preferable to carry out this exercise   in multiple short sessions with rest periods in between.

Although aerobic fitness activities should form the main part of the exercise program, a strengthening program (light to moderate intensity only) may also help to improve fitness, and may help to manage high blood pressure. 

The following precautions should be taken for those who wish to exercise with hypertension.

• Whilst high intensity exercise can be undertaken as fitness improves (usually by week 12 of the program), we do not recommend high intensity exercise at the beginning of an exercise program, as high intensity exercise can cause a short-lived spike in blood pressure. 
• Exercise is not allowed for those with a resting systolic pressure of above 180 mmHg or a resting diastolic pressure of above 110 mmHg and medical advice must be sought.
• Blood pressure medications, especially beta blockers may affect the body’s ability to handle heat and care should be taken in high temperatures or if body temperature is significantly increasing.
• Beta blockers can also predispose to low blood sugars whilst exercising so it’s important to monitor   for symptoms such as dizziness.
• Especially when taking medication, it is important to perform a brief cool down—not just stop   suddenly—to reduce the chance of a sudden drop in blood pressure.
• If any symptoms like chest pain and dizziness occur exercising should be stopped and medical   advice sought.. 
• People with hypertension often have other conditions and it is important to follow the guidelines for exercising with all relevant conditions.

Key references:

The physician's role in prescribing physical activity for the prevention and treatment of essential hypertension. 

How does exercise treatment compare with antihypertensive medications? A network meta-analysis of 391 randomised controlled trials assessing exercise and medication effects on systolic blood pressure. 

Cardiorespiratory fitness, exercise, and blood pressure. 

Key organisation:

British Heart Foundation.

American Heart Association.

American College of Sports Medicine.