We constantly hear about how dangerous high blood pressure is, but what do we know about low blood pressure? Surely we want to strive for low blood pressure and a low resting heart rate like we hear professional athletes have? Well, the answer to that is, ‘yes, and no’. While it is healthy to have low blood pressure if there are no side effects, it can be extremely unhealthy and dangerous if it does cause side effects. Like high blood pressure, low blood pressure comes with its own health risks, and some of them are extremely serious – even life threatening. We’re not just talking about dizziness or fainting. Think oxygen deprivation, heart and brain damage, and shock…
What Is Low Blood Pressure?
Blood pressure is a measurement of pressure in the arteries during the active and resting stages of each heartbeat. In medical terms, low blood pressure, or, hypotension, occurs when blood pressure is less than 90/60 mm Hg. Blood pressure readings include two numbers – the first higher number is a measure of systolic pressure, which is the pressure generated by the heart pumping blood through your arteries. The second is diastolic pressure, which is the amount of pressure in your arteries during the rest period between heartbeats. Optimal blood pressure is less than 120/80 mm Hg.
There is no need to be concerned about low blood pressure unless you are experiences symptoms, meaning there are problems and risks being created. Athletes, for example, generally have a lower blood pressure and slower heart rate than people who aren’t particularly fit. Non-smokers and people who have a healthy diet and maintain a regular, healthy weight also usually have lower blood pressure than overweight people and smokers. But those of you who have experienced dizziness, nausea, weakness and fainting on a regular basis would be all-to-familiar with the side effects that can occur from low blood pressure…
Symptoms Of Low Blood Pressure
Blood pressure isn’t always the same, meaning a reading one day might differ to another day, depending on the position of your body, your breathing rhythms, stress level, physical condition, medications and diet. People who do tend to have low blood pressure, or find that their blood pressure drops suddenly, often do experience some of the symptoms over and over again. These can include:
- Dizziness or light-headedness
- Difficulty concentrating
- Blurred vision
- Cold flushes
- Nausea and vomiting
- Rapid, shallow breathing
If you have consistent low blood pressure readings but feel fine, then that generally means there is no need for concern. Even occasional bouts of dizziness or weakness might just be a case of dehydration or too much sun. In these instances, the issue is likely to be more about how quickly your blood pressure drops, rather than how far it drops. However, these symptoms can potentially point to more serious health problems, so it is important to note what you were doing at the time and see your doctor.
Different Types Of Low Blood Pressure
Hypotension can be broken down into different categories, depending on the cause and some other issues. Doctors often use these categories to decipher the seriousness of a patient’s low blood pressure, as well as determine treatment, if any is necessary.
Orthostatic, or postural hypotension, occurs when you stand up. The sudden drop in blood pressure when moving from a seated or lying position to upright can cause faintness and dizziness. Usually, your body will compensate for the blood rushing to your legs as you stand by automatically increasing your heart rate and constricting blood vessels, enabling enough blood to return to the brain. But there is a failure in this function for people with postural hypotension, and this leads to a drop in blood pressure, which can cause blurred vision, dizziness and fainting.
Several factors can contribute to orthostatic hypotension, including dehydration, long-term bed rest, pregnancy, heart problems, diabetes, burns, excessive heat and large varicose veins. Certain medications can also contribute to postural hypotension, especially those that treat high blood pressure.
This sudden drop in blood pressure can occur after eating, and is caused by the large amount of blood flowing to the digestive tract after a meal. The body usually counteracts this by, again, increasing your heart rate and constricting blood vessels to maintain a normal blood pressure, but a failure can occur, leading to dizziness and fainting due to low blood pressure. This condition mainly affects older adults, and can occur in people taking medication for high blood pressure or Parkinson’s disease.
Neurally Mediated Hypotension
This is also known as ‘the fainting reflex’, neurocardiogenic syncope, vasodepressor syncope, the vaso-vagal reflex, and autonomic dysfunction. It causes blood pressure to fall after standing for a prolonged period of time, and can result in dizziness, nausea and fainting. This type of hypotension usually affects younger people, and it is believed to occur because of a miscommunication between the brain and the heart. It is generally a case of the body not making appropriate adjustments to blood pressure when gravity causes a large amount of blood pools to your legs. Instead of reading blood pressure as too low, nerves in the left ventricle of the heart signal the brain that blood pressure is too high, causing the sudden plummet.
Causes Of Low Blood Pressure
Everyone’s bodies are different, and what is considered low blood pressure for you might be normal for someone else. That’s because most doctors only consider chronically low blood pressure to be too low if it causes noticeable symptoms, like the ones listed above. If your blood pressure reading is below 90/60 mm Hg, on either the systolic or diastolic pressure, or both, then it is technically considered low.
A sudden drop in blood pressure can be dangerous. For example, dropping 20 mm Hg, from 110 systolic to 90 systolic can cause an inadequate blood supply to the brain and can result in dizziness or fainting. Larger plunges of blood pressure, caused by uncontrolled bleeding, severe infections or allergic reactions, can be life-threatening.
You may also like: