People naturally understand that losing blood is bad for them. Low blood volume can also affect the systems within our body, including blood pressure.
If we want to be technically accurate, blood is the postman that delivers all the essential nutrients throughout our body. Without these nutrients, we won’t be able to experience the beauty of life, let alone function.
Blood volume must be kept at an optimal level based on how vital blood is. If enough blood is lost, many problems and conditions come about.
Let’s find out how low blood volume causes low blood pressure.
The Levels of Blood in Our Body
Before determining whether hypotension is associated with our blood amount, let’s familiarise ourselves with the concept.
What Is Blood Volume?
As the name indicates, volume refers to the total amount of blood circulating throughout our bodies. It considers those within our veins, the chambers of the heart, and the capillaries, to name a few.
This isn’t isolated to red blood cells only. White blood cells, plasma, and platelets also comprise this level.
The total amount of blood circulating in a person depends on their weight and size. On average, an adult has approximately five litres of blood circulating. Women have a lower volume than men, but it increases by half when pregnant.
What Determines the Volume?
Our blood volume depends on the amount of water and sodium we consume. However, this is only one side of the coin. If something comes in, it must also come out. In terms of blood, the volume will continuously rise without an exit.
The path of exit for the volumes of blood lies in the lungs, the skin, and the kidneys, to name a few.
The kidney, for example, plays a central part in keeping levels equal. If too much water and sodium are ingested, the kidneys filter it through urine.
What Happens if Blood Volume is Low?
Hypovolemia occurs when the body’s blood volume drops too low. It occurs when a person has lost at least 15% of their volume.
Additional causes of the condition include wounds where people bleed out, diarrhoea, vomiting, and internal bleeding.
When levels are this low, people typically experience a slew of symptoms. These include dizziness, muscle cramps, fatigue, and darker urine. More serious symptoms include excessive sweating, shortness of breath, and unconsciousness.
In its most extreme form, people will go into hypovolemic shock, which, if left untreated, may result in organ failure and, eventually, death.
The Connection Between Blood Volume and Blood Pressure
Blood volume determines how much force is exerted on the walls of your blood vessels. When blood volume decreases, blood pressure drops as well. In response, the body narrows the blood vessels to maintain adequate circulation. However, in severe hypovolemia (low blood volume), the body may struggle to compensate, leading to inadequate blood flow to tissues and organs.
On the other hand, an increase in blood volume causes the arteries and veins to expand, resulting in higher blood pressure. This condition, known as hypervolemia, is often linked to fluid retention issues, commonly seen in individuals with kidney or liver dysfunction. When the body cannot effectively regulate fluids, excess volume builds up in the bloodstream, which strains the heart and blood vessels.
Maintaining a balanced blood volume is essential for stable blood pressure and cardiovascular health. Proper hydration, electrolyte balance, and organ function help ensure the body can regulate fluids effectively.
How To Treat Lower Blood Volumes
If hypovolemia reaches severe levels for any reason, then immediate care must be administered. Depending on the cause of the volume loss, it can be done in many ways.
For instance, if a person is bleeding out, a doctor would first stop the bleeding. Afterwards, an IV drip will help replace the lost blood volume using crystalloids. These saline solutions help to refill the blood volume, but they may decrease platelets and other components in the blood.
When this happens, doctors can introduce more transfusions using plasma and red blood cells, depending on what is lacking.
How Long Does Treatment Last
Several factors influence the duration of treatment for hypovolemic shock, with the primary concern being whether severe damage has occurred, particularly to critical organs like the brain and kidneys. Since this condition can be life-threatening, doctors first assess the extent of organ damage before determining the course of care.
Replenishing lost blood volume is a top priority, but recovery varies from person to person. Even with IV fluids or blood transfusions, some individuals may take longer to stabilise due to different factors, such as:
- Severity of the shock,
- Amount of blood lost,
- Extent of injury, and
- Underlying health conditions
It could impact fluid absorption and circulation. Each case is unique, requiring careful monitoring and tailored medical intervention to restore proper blood flow and prevent complications.
Balance in All Things
Low blood volume is a serious condition. The loss of volume leads to many symptoms, including low blood pressure.
As with all things, one should always strive for balance. It includes the volume of blood. A touch too high or too low could introduce complications to a person that could result in death.
While treatment is available, there is a significant element of risk involved. If any symptoms appear, the best thing to do is to check in with a doctor immediately.
The knowledge of blood volume is essential, but it must also be balanced with the right actions. Today, learn about potential life-saving first aid practices through CPR First Aid’s Liverpool course.