When you have your blood pressure measured, you get two values, an upper and a lower value. Systolic blood pressure is the upper number. This is the highest value your blood pressure reaches when your heart is beating and pushing blood through your body. Diastolic blood pressure is the lower number. This is the lowest value your blood pressure reaches when your heart relaxes between beats. Low blood pressure is generally considered to be less than 90 millimeters of mercury (mm Hg) for the top number (systolic) or 60 mm Hg for the bottom number (diastolic). If your lower blood pressure is too low naturally, it is unlikely to cause you any problems and does not need to be treated. Low blood pressure can sometimes be caused by medications or be a sign of another health problem. This can sometimes lead to problems such as falls, fainting, and dizziness, and may need to be investigated and treated.
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What are the symptoms of low blood pressure
When your blood pressure lower reading is too low, this condition often has no symptoms, but can sometimes mean that not enough blood is flowing to your brain or organs. This can cause symptoms such as:
- Feeling lightheaded, faint or dizzy.
- Swaying feeling
- Nausea (feeling sick to your stomach)
- blurred vision
- a general feeling of weakness
- feeling of confusion
- sudden onset of heart palpitations (palpitations).
If you experience these symptoms, you should stop what you are doing and sit down or lie down if you fall, and drink some water. Not only are the symptoms uncomfortable, but they could mean you are at risk of falling. They could also be a sign of another health problem. Sometimes changes in your posture can cause a drop in blood pressure , such as when you go from sitting or lying down to standing. You may experience the above symptoms, such as dizziness or fainting, when you stand up. This is called postural hypotension or orthostatic hypotension. It is caused by changes in the arteries that occur with age and when you take medications to lower blood pressure.
Blood pressure too low: causes
Some people have blood pressure that is naturally low. That is, there is no specific cause or reason for it. It may be the result of a healthy lifestyle and a fit and active lifestyle, and your genes may also play a role. Your blood pressure fluctuates throughout the day. It may drop if you’ve just eaten something while blood is being transported to the intestines, if you stand for long periods of time, if you’re dehydrated, and if the temperature is high.
There are a number of other possible causes of low blood pressure:
Low blood pressure can be caused by medications. These include medications to lower blood pressure, antidepressants, and beta blockers used to treat heart problems.
Low blood pressure can also be caused by a disease or health problem.
- Diabetes can interfere with normal blood pressure control because it can affect hormones and the nerves that lead to the blood vessels. If the nerves are affected, blood pressure may drop when you stand up because the blood vessels cannot adjust quickly enough to the new position.
- Neurological diseases (diseases affecting the nervous system). For example, Parkinson’s disease. These can affect the autonomic nervous system, which controls what happens in our bodies, including the dilation and constriction of blood vessels. When blood vessels are dilated, blood has more room to flow, and blood pressure drops . Medications prescribed to treat Parkinson’s can also cause low blood pressure, especially postural hypotension.
- Problems with your adrenal glands. For example, Addison’s disease, an infection or a tumor. The adrenal glands sit just above the kidneys and produce hormones that help control blood pressure. When they are damaged, it can cause a drop in these hormones and a drop in blood pressure.
- Neurally mediated hypotension. This is a condition in which, after standing for a long time, your body sends signals to your brain telling it that your blood pressure is high, when in fact it is too low. The brain then signals the heart to beat more slowly, and your blood pressure drops.
- Heart problems. Heart problems such as heart failure or heart attack can cause low blood pressure because the heart can’t pump blood around the body as well as it should.
- Anemia. In this case, the number of red blood cells is lower than normal, or the amount of hemoglobin – the part of the blood that carries oxygen – is lower than normal.
- Severe injuries and shock. Severe injuries, burns and shock can cause a drop in blood pressure. For example, if you lose a lot of blood, if you have an allergic reaction called anaphylactic shock, or if you have shock caused by a bacterial infection.
How to diagnose the problem
Like high blood pressure, low blood pressure can be easily detected by measuring your blood pressure. If you feel dizzy or faint when you stand up, you should have your blood pressure measured while lying down and again while standing. You may be offered a tilt table test. This involves lying down on a table that is initially horizontal and then slowly tilts so that you are in an almost upright position – as if you were standing. Your blood pressure and pulse will be taken, and any symptoms you feel will be recorded. You may also have a blood test to determine the level of certain hormones.
What treatment is used
If your blood pressure is naturally low and does not cause you any problems, it probably does not need to be treated. If you have symptoms and your doctor or nurse thinks you would benefit from treatment, he/she will try to find the best way to treat you. Treatment depends on the cause.
A change in medication. If your primary care doctor thinks your blood pressure is caused by a medication you are taking, he or she may try an alternative medication or a different dosage.
Hormone replacement. If your low blood pressure is caused by a change in certain hormones, such as if your adrenal glands are damaged, you may be referred to a specialist called an endocrinologist. He or she may prescribe hormone replacement medications for you.
Medicines to stimulate your nerves. If you have a neurological condition, you may be given medicines to stimulate your nerves.
Medicines for low blood pressure . These medications constrict your blood vessels or expand blood volume to increase blood pressure. They are very rarely needed, as the above treatments and the changes you can make yourself are usually enough.
What you can do for yourself
There are other things you can do for yourself to help relieve your symptoms.
- Wear supportive elastic stockings (compression socks). They put extra pressure on your legs, which helps blood flow and increases blood pressure. For some people, this may be enough, but talk to your primary care doctor first, as they are not suitable for everyone.
- Slowly get up from a sitting or lying position. You can also try other simple movements to get your circulation going before you stand up, such as stretching and bending your legs.
- Avoid standing for long periods of time.
- Drink enough water throughout the day, about 2 liters, so you don’t become dehydrated.
- Eat little and often throughout the day. This will help you avoid low blood pressure after eating.