Sudden BP Increase (Rise in Blood Pressure) Causes

A sudden increase in blood pressure is a cause for concern, whether you suffer with hypertension (high blood pressure) or not. Depending on how high the blood pressure rises, it can lead to serious complications and may even be life threatening. Blood pressure refers to the force exerted by circulating blood on the walls of the major blood vessels. It is measured in the units of millimeters of mercury (commonly abbreviated as mmHg).

Measurements of blood pressure are stated in pairs of values. Normal blood pressure in humans is considered to have a value of 120/80 mmHg. The first value (120 mmHg) refers to the systolic blood pressure that corresponds to the systolic phase of the cardiac pumping cycle. The second value (80 mmHg) refers to the diastolic blood pressure that corresponds to the diastolic phase of the cardiac pumping cycle. For most people, normal blood pressure hovers around 120/80 mmHg.

Does Blood Pressure Change or Stay the Same?

Blood pressure does not remain constant throughout the day. There are variations in blood pressure due to levels of activity and states of the mind. Aging also affects blood pressure. Normal systolic blood pressure can vary between 90-119 mmHg, whereas normal diastolic blood pressure can vary between 60-79 mmHg. The normal reference value of 120/80 mmHg is, therefore, the upper bound of the normal blood pressure. Above this level, one enters the pre-hypertension and hypertension categories.

Sometimes, there may be acute changes in blood pressure. This may result in a minor increase in the blood pressure for a short period of time. However, blood pressure returns to the normal level within a short time. For this reason, diagnosis of hypertension requires at least three separate blood pressure measurements at 5 minute intervals. If this transient phenomenon is not taken into account, one may erroneously mistake an acute spike in blood pressure to be an indicator of a hypertension disorder.

Factors that Determine Blood Pressure

The blood pressure at any moment is determined by multiple factors. Three major factors that influence the blood pressure include:

  • The rate and force with which the heart contracts.
  • The diameter of the blood vessels.
  • The viscosity and volume of the blood.

Other than the major factors mentioned above, blood pressure can also be influenced by nerve impulses, electrolytes and hormones. Activities such as standing, lying, sitting up or running also affect the blood pressure. Even the ambient temperatures in hot and cold weather conditions can affect the blood pressure.

Read more on sudden severe headache.

Causes of Sudden Increase in B.P.

Increased physical activity

An increase in physical activity usually causes an increase in blood pressure. Activities such as running, walking, swimming and dancing increase the need for oxygen in the muscles. This increases the rate of breathing. The heart also starts to pump faster in order to meet the increased oxygen demand of the muscles all over the body. The faster heart rate increases the blood pressure.

In normal individuals, an increase in blood pressure caused by physical activity is minor and temporary. The blood pressure returns to normal after the physical activity ceases. However, the increase in blood pressure may be significant in individuals who have problems with blood pressure control.


Both physical and psychological stressors can raise the blood pressure. In fact, psychological stress is one of the major causes of sudden increases in blood pressure. Psychological stressors that can result in an acute increase in blood pressure include emotions such as fear, anxiousness, and anger. The increase in blood pressure due to psychological stress is mediated by an increase in the level of stress hormones in circulation and nerve impulses from the brain to the heart.

A person experiencing a sudden increase in blood pressure due to emotional stress should try to calm down. Taking deep breaths, focusing on pleasant thoughts and just sitting quietly may help in restoring the blood pressure to normal levels. Chronic stress, such as worrying about relationships and money, can lead to chronic hypertension.


Smoking nicotine is one of the most common causes of sudden increases in blood pressure. Nicotine and other chemicals contained in cigarette smoke reduce oxygen levels in the blood. This results in an increase in the heart rate. The heart may also beat harder with each cycle. The lumen of the blood vessels also narrow down, which further contributes to the increase in blood pressure.

An acute rise in blood pressure after smoking may last from 20 minutes to 120 minutes. In chainsmokers, the blood pressure may not return to normal at all. The red blood cell count increases and chronic hypertension may also occur in the long term.

Chemical substances

Several types of chemicals contained in herbs, medicinal and illicit drugs, and alcohol can cause a sudden increase in blood pressure. An example of a herb that can cause an acute increase in blood pressure is licorice. The amount of licorice consumed determines the extent of the rise in blood pressure. Alcohol consumption initially causes a small drop in blood pressure.

However, blood pressure rises with continuous consumption of alcohol. Illicit drugs that can cause sudden increases in blood pressure include methamphetamines and cocaine. Examples of medicinal drugs that can cause an acute rise in blood pressure include acetaminophen, ibuprofen, and anti-allergy medicines.

Dietary Sodium

In modern times, salt has become one of the major factors that causes an increase in blood pressure. The majority of processed foods contain high concentrations of salts. The high sodium content in these processed foods, which constitute a major proportion of our modern diets, is rapidly absorbed from the intestine.

People with kidney conditions are especially vulnerable to hypertension caused by increased salt consumption. Therefore, a low sodium diet is advised for individuals suffering from kidney diseases and hypertension.

Cold weather

Acute changes in blood pressure could also be caused by the ambient temperature. In general, hot weather tends to cause a drop in blood pressure and cold weather tends to cause a rise in blood pressure. These changes in blood pressure are typically very small.

However, even slight increases in blood pressure could have an effect in people suffering from hypertension. In cold weather, the body tries to conserve heat by constricting the peripheral blood vessels. This increases the workload on the heart as it tries to push blood through the narrow blood vessels.

More Related Topics