5.5 Hypertension
Overview
Normal blood pressure is defined as less than 120/80 mm Hg in adults. Hypertension refers to chronically elevated blood pressure greater than 120/80 mm Hg. Hypertension is very common, affecting millions of individuals worldwide. See Figure 5.26[1] for an image of a health care professional obtaining a blood pressure reading.
There are several classifications of blood pressure based on the systolic and diastolic readings. See Table 5.5 for classifications of hypertension according to the American Heart Association.[2]
Table 5.5. Blood Pressure Classifications[3]
| Blood Pressure Classification | Systolic (mm Hg) | Diastolic (mm Hg) |
|---|---|---|
| Normal | Less than 120 | Less than 80 |
| Elevated (Prehypertension) | 120-129 | Less than 80 |
| Hypertension Stage 1 | 130-139 | 80-89 |
| Hypertension Stage 2 | 140 or higher | 90 or higher |
| Hypertensive Crisis | Higher than 180 | Higher than 120 |
Causes of Hypertension
Hypertension can be due to a primary cause or as a secondary cause. Primary hypertension is the most common type of hypertension and has no identifiable cause. It typically develops gradually over time and is influenced by various risk factors such as genetics, age, race, diet, lifestyle, and stress.
Secondary hypertension is the result of an underlying medical condition or medication. Conditions such as kidney disease, hormonal disorders, or the use of medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), pseudoephedrine or phenylephrine, and estrogen-containing birth control pills can contribute to secondary hypertension. Additionally, medical conditions like diabetes, kidney disease, and sleep apnea can increase one’s risk of developing hypertension.
Risk factors for developing hypertension include age, family history, and lifestyle factors. Individuals with obesity, diets high in sodium, excessive alcohol intake, chronic stress, and limited physical activity are at higher risk for developing hypertension.[4] For this reason, health teaching about lifestyle modifications is essential for nurses to provide to clients experiencing prehypertension or hypertension.
Assessment
Many individuals with hypertension have no symptoms and are unaware of the condition until they have an elevated blood pressure reading collected. If individuals have an elevated blood pressure reading, providers will typically repeat the reading at another appointment before making a diagnosis and beginning treatment. They may ask the individual to collect blood pressures at various dates/times at home or when out in the community and keep a tracking log. Many individuals with hypertension are asymptomatic although some develop symptoms as a result of hypertension, such as a headache, dizziness, or fainting.[5] Untreated hypertension can lead to significant health complications such as myocardial infarction (heart attack), heart failure, cerebrovascular accident (stroke), vision loss, kidney damage.
Diagnostic Testing