Dehydration And Blood Pressure: What’s The Connection?

Are you concerned about dehydration causing blood pressure changes in your body? Worry no more and find your answers in this comprehensive article!

Quick Summary

• Dehydration is caused by excessive loss of fluids and can directly or indirectly affect the blood pressure levels in the body.
• High blood pressure can be seen in dehydrated individuals accompanied by high levels of sodium in the body.
• Low blood pressure is due to dehydration due to the decreased blood pressure in the body. 

High blood pressure seems tricky to manage especially when one can’t seem to figure out the root cause of this condition. There are various reasons why one can face blood pressure differences.

It is also pretty common to see these BP levels rising or lowering from time to time since many factors directly or indirectly affect blood pressure.

If you suspect a change in your BP levels due to dehydration, have a good read of this article. You’ll get to know the various causes, effects, and symptoms linked to this condition.

What Does Dehydration Mean?

Dehydration is the condition where the body loses more electrolytes and fluids than its retention or consumption. When a person becomes dehydrated, it is because they are not drinking enough water. Excessive sweating or urinating are among other reasons why dehydration occurs.

Extreme dehydration can be dangerous if a person suffers from it for a long period of time. This condition can affect the normal body’s function in multiple ways and lead to dizziness, headaches, and changes in blood pressure.  

What Are The Various Reasons Behind Dehydration?

While most of the time, dehydration is caused because of not drinking enough water, it can also be caused by various other reasons, such as:

• Diarrhoea: This condition leads to serious loss of fluids in the body. When a person has diarrhoea, the food is processed in a shorter time by the digestive system. Moreover, the water is not absorbed when it reaches the large intestine and is directly excreted along with faecal matter, eventually leading to dehydration.
• Excessive sweating: When one sweats a lot, their stored body fluids are released. In case of insufficient fluid or water intake, excessive sweating can cause dehydration.
• Vomiting: Similar to the condition of diarrhoea, vomiting causes rapid loss of body fluids and minerals. People who are nauseous or vomiting may find it difficult to retain water, putting their life at risk.

Along with this, frequent urination and fever can also influence the amount of water that the human body holds.

The Connection Between Dehydration And Blood Pressure

The connection between dehydration and blood pressure seems clear and can affect both high and low BP.

High blood pressure and dehydration

In the case of HBP, the systolic blood pressure is above 130 mm Hg, whereas the diastolic blood pressure is above 80 mm Hg. Many studies have also reflected that dehydration can cause an increase in blood pressure levels and eventually lead to hypertension.

The concentration of sodium increases during the state of dehydration. Due to this, the brain sends several signals to the human body’s pituitary gland, which then secretes vasopressin.

This vasopressin is called an antidiuretic hormone or ADH and plays an important role in maintaining osmotic balance, kidney functioning, sodium regulation, and blood pressure regulation.

The kidneys will reabsorb water when the body is dehydrated rather than flush it out. The blood arteries may narrow if your vasopressin levels are high. The condition that leads to this increase in blood pressure is called vasoconstriction.

Low blood pressure due to dehydration

Another way the dehydrated body can react is by reflecting a lowered blood pressure.

Dehydration can change the systolic reading of blood pressure to less than 90 mm Hg, whereas diastolic can decrease to 60 mm Hg. It is important to take BP reading often and analyse it using a blood pressure reading chart to ensure there is no risk factor lying.

The blood volume directly depends upon the fluid quantity that a person consumes. This blood volume is the net amount of fluid that moves through the circulatory system at any given time. The decrease in blood volume is referred to as hypovolemia.

The reduced blood volume eventually leads to changes in blood pressure (lowering effect). This can also make an individual feel dizzy, tired, and weak. A low BP can also lead to shock and might need immediate help.

Symptoms Of Dehydration

An irregular urine pattern is the biggest sign of a dehydrated body. It should be noted that being thirsty is not always accompanied by dehydration. This is why it is necessary not to wait to be thirsty before drinking water.

• Dry skin
• Dry mouth
• Weakness in the muscles
• Headache
• Less tear production
• Dizziness
• Constipation
• Lethargy

With the increase in the severity of the condition, one may experience different symptoms that may or may not include the following:

• Excessive thirst
• Less sweating
• Severe headaches
• Sunken eyes
• Shrivelled skin
• Low blood pressure
• Rapid breathing
• Dark urine
• Shock

Although it might seem pretty uncommon for babies to have higher blood pressure, it is generally not the case. Infants can face this condition due to dehydration, and to recognise the signs of less body fluid, one should note the following:

• Dry mouth
• No tears while crying
• Irritation
• Sunken cheeks
• Dry diaper for three or more hours

How To Treat Dehydration For Maintaining Blood Pressure?

The first and foremost step to prevent or cure dehydration is to drink enough water. This will help decrease the chances of blood pressure changes.

It is suggested that a person must consume six to eight glasses of water in a day, but this can vary from person to person.

Fresh fruit juices can be consumed in diluted forms to avoid strain on the stomach and induce hydration. One should strongly avoid coffee, soda, tea, and alcoholic drinks as they are diuretics and can dehydrate the body even more.

Conclusion

Being dehydrated is directly linked to changes in blood pressure levels. Therefore, it is highly necessary to note the changes in the body to suspect dehydration and consume fluids.

In case dehydration turns serious, it is best to refer to a doctor as soon as possible. This condition may then be treated with the help of intravenous fluids.

It is also important to note that dehydration and blood pressure changes can be due to medications. Talk to a doctor if you suspect uncontrolled dehydration and high or low blood pressure.