Hypertension

Disease class: Vascular diseases

Types

• Essential hypertension
• hypertension, Malignant
• hypertension, Pregnancy-induced
• hypertension, Renal
• Hypertensive retinopathy
• Masked hypertension
• White coat hypertension

 

Also known as

• Hypertensive diseases
  
• HTN (often written in medical records)
• High blood pressure

 

In brief

• Hypertension is a risk factor for many diseases, such as heart failure and renal failure.
• Hypertension is a risk factor for many sudden onset events, such as stroke.
• Minimising hypertension in the population significantly reduces the number of these diseases.

What is "high"?

European Heart Journal:34;2159–2219

• A commonly cited "normal" or "healthy" blood pressure for the average adult is 120/80. This means that the blood pressure is 120 mmHg during systole and 80 mmHg during diastole. The mean arterial pressure would be around 93 mmHg.
• Blood pressure varies with age. Children tend to have a lower blood pressure and old adults tend to have a higher blood pressure. 
• Frequent exercisers tend to have lower blood pressure values.
• In an acute situation, it is important to consider what is normal for the patient. Even a blood pressure of 120/80 could be high for them.

Symptoms and signs

• Hypertension is usually asymptomatic and detected by routine blood pressure measurement.
• Symptoms are more common with hypertensive crises or complications of chronic hypertension.
• Headache
• Light-headedness
• Visual disturbances

Risk factor for:

• Stroke
• Ischaemic heart disease
• Peripheral vascular disease
• Heart failure
• Dementia

 

Complications

• Hypertensive retinopathy
• Hypertensive nephropathy
• Hypertensive encephalopathy

 

Acute severe hypertension (urgency/crisis/emergency)

• When hypertension is severe enough it is known as a hypertensive urgency.
• The combination of hypertensive urgency, and signs of acute organ damage is a medical emergency. This is known as a hypertensive crisis, hypertensive emergency or malignant hypertension. Within minutes of a hypertensive crisis there is a significant risk of complications such as stroke.
• Rapid reduction in blood pressure can precipitate complications such as strokes.

Aetiology and pathophysiology

• If successful treatment of another disease causes the hypertension to completely resolve, then it is called secondary hypertension. The hypertension is "secondary" to that disease.
• There are many causes of secondary hypertension, particularly kidney dysfunction and endocrine disorders.
• Most cases of hypertension are essential hypertension (also called primary hypertension). This means that the body has failed to regulate the blood pressure within healthy limits, usually as a result of ageing. These patients may have no other medical conditions. Even if these patients have another medical condition, and it is completely reversed by treatment, the hypertension will not resolve.

Management

• Detect and confirm hypertension.
• Establish whether hypertension is primary or secondary. If secondary, what is the cause?
• Aim to control blood pressure values, minimising time out of target range.

Reducing blood pressure values to a target level should be done over the course of days. Rapid drops in blood pressure can precipitate strokes. 

• Lifestyle changes. Dietary changes. Reduction of salt intake.
• Medical therapy
• Vasodilator therapy