Low Blood Pressure
What is low blood pressure?
First of all, blood pressure refers to the pressure in the arteries throughout the body. This pressure is the driving force which sends the blood from the higher pressure regions (arteries) to the lower pressure regions (the organs and veins). When measuring an individual’s blood pressure, two values are given: the systolic and diastolic.
- Systolic pressure refers to the pressure in the arteries when the heart muscle contracts and pushes the blood into the arteries.
- Diastolic pressure refers to the pressure in the arteries when the heart is relaxed.
Blood pressure is displayed with the systolic pressure over the diastolic. Normal blood pressure is considered 90 to 120 for systolic and 60 to 80 for diastolic, with the average falling around 120/80 (systolic / diastolic).
How do I know if I have low blood pressure?
Unlike high blood pressure, low blood pressure (which is also referred to as hypotension) is not identified by taking a simple measurement. It must be determined by the presence of symptoms as well as the measured value. This is the case because “normal blood pressure” differs from one person to the next. For example, one person could have a normal blood pressure reading of 100/60, yet not exhibit any symptoms of low blood pressure. Thus, they are considered perfectly healthy. On the other hand, an individual who is normally at 120/80 and then drops to 100/60 will quite possibly display the symptoms of hypotension.
Is low blood pressure always considered unhealthy?
No, definitely not. Individuals who are physically fit with strong cardiovascular systems are considered healthy and actually have a decreased risk for heart attack and stroke. As long as these individuals don’t exhibit any of the telltale symptoms for hypotension, there is no cause for concern. However, low blood pressure accompanied by any of the symptoms discussed below could indicate that the low blood pressure is a problem.
What are the symptoms of hypotension?
The most common symptoms of hypotension are dizziness, lightheadedness and fainting, which are caused by a decrease in blood flow to the brain. This causes the brain cells to receive a less than desirable amount of oxygen and nutrients. If dizziness and / or lightheadedness are experienced after an individual stands from a lying or sitting position, the condition is referred to as orthostatic hypotension.
Orthostatic hypotension results because changing the body’s posture from sitting (or lying down) to standing causes a large volume of blood to rush to the lower extremities, resulting in a decrease in blood pressure. Someone who has low blood pressure to begin with is more likely to experience dizziness or lightheadedness when standing up. Individuals with a normal blood pressure will also experience a decrease in blood pressure when standing up, but their bodies are better able to accommodate and are much less likely to feel dizzy or lightheaded.
Besides dizziness, lightheadedness and fainting, other symptoms of hypotension include:
- Inability to concentrate
- Blurred vision
- Nausea
- Cold, clammy skin
- Shallow and rapid breathing
- Depression
- Fatigue
- Thirst
If the hypotension is more severe, a lack of pressure to deliver blood to the coronary arteries will cause a decreased blood flow to the heart, resulting in angina (chest pain) or heart attacks. Decreased blood flow to the kidneys could cause kidney failure, leading to a build-up of urea and other waste products in the blood.
Is there anything I have to be aware of when exercising with low blood pressure?
Individuals who have hypotension need to be aware of orthostatic hypotension when working out. Dizziness, lightheadedness or even fainting can result during or after a workout if the proper precautions are not taken.
First of all, exercises involving postures that put the head at a lower position than the heart put one at risk for orthostatic hypotension. In addition, positioning the body in a prone or supine position with the head level with the heart could pose a risk.
If you have hypotension, the following exercises must be performed with caution:
- Bench press
- Decline press
- Bent-over rows
- Reverse flyes
- Sit-ups
- Back extensions
- Some yoga poses
- Aerobic classes (involving bending at the waist)
You do not necessarily have to avoid these exercises completely; just make sure to get up from the position slowly, and if you do feel dizzy, stay in a seated position until the feeling passes. If you find that these precautions don’t make much of a difference and the lightheadedness is still prominent, I would steer away from these exercises and replace them with other exercises that will work the same muscle groups, but require a posture with your head above your heart at all times. For example, you could replace bench presses with seated chest presses and bent-over rows with mid-rows.
Hypotension and Cardio
People with low blood pressure also experience orthostatic hypotension when they stand still immediately after doing a standing cardio workout (e.g., running, elliptical) or even doing lunges or squats. In these cases, the condition occurs because stopping and standing still after a leg-focused workout will cause blood to pool in the lower extremities, which causes a decrease in blood flow to the brain.
This can be prevented by doing a gradual cool-down after any standing cardio workout (at least 5 to 10 minutes of cardio at a low intensity, to gradually bring your heart rate back to normal) and by walking around after doing lunges or squats. This protocol is strongly recommended because your heart requires the contraction of the leg muscles to help return the blood to the heart and the brain.
If dizziness remains an issue or if you experience any of the other symptoms mentioned, consult your doctor.
