Having lower blood pressure is generally considered to be positive because high blood pressure (hypertension) is linked with conditions like heart disease, heart attacks, and strokes. However, blood pressure that’s too low (hypotension) can be equally damaging.
Here, we’ll explore what low blood pressure is and its causes – as well as how it can be increased with lifestyle changes and medical treatment.
What is low blood pressure?
With every heartbeat, the heart pumps blood through our arteries to transport oxygen and nutrients around the body.
Blood pressure is a measure of the amount of force used during the pumping process. It’s calculated by two measurements: systolic pressure and diastolic pressure.
- Systolic pressure is the amount of pressure in the arteries when the heart beats and squeezes blood into them. Pressure in the arteries is highest during this stage.
- Diastolic pressure is the amount of pressure in the arteries when the heart rests in between beats and the blood flows back to the heart through the veins. Pressure in the arteries is at its lowest during this stage.
Your blood pressure reading will appear as your systolic pressure followed by your diastolic pressure. For example, if your systolic blood pressure is 120mmHg and your diastolic blood pressure is 80mmHg, your blood pressure reading will appear as 120/80.
According to the NHS, the ideal blood pressure ranges are between 90/60 and 120/80. Readings of 140/90 or above are considered high blood pressure (hypertension), while 90/60 or less is considered low blood pressure (hypotension).
Blood pressure can naturally fluctuate in response to everyday activities, and is likely to be lower when we’re sleeping, for example, as opposed to walking around.
However, if your blood pressure is so low that it makes you feel tired and dizzy, it may be a sign of an underlying health condition or a side effect of lifestyle factors (such as long-term bed rest) or certain medications.
Below, we’ll cover some of the different types of low blood pressure.
What are some types of low blood pressure?
There are several types of low blood pressure (hypotension), all of which have different triggers and symptoms.
These include…
Postural hypotension
Postural hypotension (also known as orthostatic hypotension) is when blood pressure drops suddenly when standing up.
As the body takes time to adjust to this position change, people with postural hypotension may feel dizzy or lightheaded. Postural hypotension is the most common form of low blood pressure and older adults are most at risk.
Conditions that affect the autonomic nervous system, such as Parkinson’s disease, diabetes, and thyroid disease are closely linked with postural hypotension. In fact, research shows that between 30% and 50% of people with Parkinson’s disease, and around 30% of people with diabetes, are affected by postural hypotension.
Postprandial hypotension
Postprandial hypotension is a drop in blood pressure that occurs one to two hours after eating.
Again, research shows that mature adults with autonomic nervous system diseases like Parkinson’s, as well as those with high blood pressure, are most at risk.
Neurally mediated hypotension
Neurally mediated hypotension is a drop in blood pressure that occurs after standing for long periods of time.
This type of low blood pressure is most common in young adults and children and is thought to be the result of miscommunication between the heart and brain.
Severe hypotension
A severe drop in blood pressure can sometimes occur during times of shock – for example, after experiencing a serious injury.
Multiple system atrophy
Also called Shy-Drager syndrome, multiple system atrophy (MSA) is a rare health condition that affects the central nervous system (which controls movement) and the autonomic nervous system (responsible for involuntary functions such as blood pressure, breathing, heart rate, and digestion).
Symptoms of MSA can include loss of bladder control and problems with coordination and speech, and typically appear between the ages of 50 and 60.
Other potential causes of hypotension
1. Certain medications
Low blood pressure can sometimes be a side effect of taking certain medications.
Medications such as beta-blockers and nitroglycerin, used to treat heart disease, can have this effect. As can diuretics, erectile dysfunction drugs, tricyclic antidepressants, and medication used to treat high blood pressure.
If you’re currently taking medication that causes your blood pressure to become too low, your GP may adjust your dosage or change the medication.
2. Health conditions
Various health conditions affecting the heart, liver, nerves, or hormone systems can also lead to a general decrease in blood pressure.
These include (but aren’t limited to)…
- Dehydration – for example, if you’ve been vomiting and can’t keep liquids down or have severe diarrhea
- Impaired circulation – caused by a heart condition or following a heart attack
- Pregnancy – due to the increase in demand for blood for both the pregnant mother and growing fetus
- Autoimmune conditions – such as diabetes, Parkinson’s disease, and thyroid disease
- Prolonged bed rest
- Large amounts of blood loss due to injury
- Severe allergic reaction
What are the symptoms and risks of low blood pressure?
Having low blood pressure doesn’t always cause symptoms. However, if your blood pressure is low enough to prevent your vital organs from receiving enough blood, you may begin to feel tired or unwell.
Some common symptoms of low blood pressure include…
- Fatigue
- Lightheadedness
- Nausea
- Dizziness
- Confusion
- Fainting
- Blurred vision
If left unchecked, potential complications of low blood pressure include fainting and injury from falls. And, if blood pressure is severely low, it can reduce the body’s oxygen levels and increase the risk of heart and brain damage.
You can read more about the potential symptoms of low blood pressure on the NHS website. If you continually experience symptoms of low blood pressure such as dizziness and fainting, it’s important to make an appointment with your GP.
How is low blood pressure diagnosed?
Low blood pressure can be easily diagnosed by taking a blood pressure reading. To do so, your GP or a pharmacist may use a sphygmomanometer or a digital sphygmomanometer.
If you’d prefer to measure your blood pressure at home, there are various kits available to buy. For example, Boots UK have a selection of blood pressure monitors available on their website.
You can find out more about how low blood pressure is diagnosed on the NHS website.
Note: If your blood pressure reading is outside of the recommended guidelines, it’s important to see your GP immediately.
How can low blood pressure be managed and treated?
Treatment for low blood pressure will depend on its cause. So, your GP will take into account the type of hypotension you’re experiencing and what situations are triggering your symptoms.
We’ll cover the main types of treatment for low blood pressure below.
Lifestyle changes
Sometimes lifestyle changes are enough to improve low blood pressure.
Depending on what’s causing your low blood pressure, some of the lifestyle changes that your doctor might suggest include…
1. Stay hydrated
When the water and salt content of your body is reduced, it can cause low blood pressure.
Therefore, increasing your fluid intake and, where necessary, adding more salt to your diet, can help with this. This is because having more fluid in the body (which salt can help to retain) increases the volume of blood – and having more blood in the arteries increases blood pressure.
The NHS advises drinking at least six to eight glasses of water or of a hydrating alternative each day. This is especially important if you’re unwell, exercising, or in a hot location. For more tips, you might like to read our articles; 10 tips for staying hydrated and 9 healthy and hydrating alternatives to water.
Similarly, while people with high blood pressure are often advised to limit how much salt they consume, those with low blood pressure might need to increase their intake. Your GP will be able to advise you on whether or not this is a suitable option for you and, if so, how much salt you should add to your diet.
2. Stand up gradually
Standing up gradually, especially first thing in the morning, can help to prevent sudden dips in blood pressure – particularly if you suffer from postural hypotension.
According to the NHS, doing some form of physical movement in the morning, such as stretching in bed before you get up, can help to increase your heart rate and the flow of blood around the body.
3. Consider wearing support stockings
Support stockings (also called compression socks/stockings) are tight-fitting elastic tights or socks designed to provide extra pressure to your feet, legs, and abdomen.
By doing so, support stockings can help to increase circulation, and therefore, blood pressure. Compression socks are available to buy on Amazon.
4. Try sleeping with extra pillows
Some people find that raising their head in bed – for example, by using extra pillows – is beneficial for improving low blood pressure because it helps to increase blood flow.
5. Limit caffeine and alcohol intake
Limiting caffeine and alcohol intake can help to avoid dehydration, which can cause low blood pressure.
6. Try eating smaller, more frequent meals
Eating smaller, more frequent meals can help to prevent postprandial hypotension (low blood pressure that occurs after eating).
For help with this, you might like to have a read of our article; 9 tips to prevent overeating and encourage portion control.
Lying down or sitting still for a while after eating is also thought to help.
Medical treatment
According to the NHS, very few people are prescribed medication for hypotension. This is because, in the majority of cases, symptoms can be managed with lifestyle changes.
However, in more severe cases, medication may be required. This is typically medication that increases blood volume or narrows the arteries – both of which increase blood pressure.
If your GP believes that a medication you’re taking for another health condition may be causing low blood pressure, they’ll likely recommend a change in medication, or alter your dose. This can include medication used to treat high blood pressure or Parkinson’s disease.
You can find more information about how low blood pressure is treated on the NHS website.
Final thoughts…
While having low blood pressure is often considered less serious than having high blood pressure, it can be equally dangerous for health. However, the good news is that there’s plenty of treatment options available – including simple lifestyle changes that can make all the difference.
For further reading, head over to the general health section of our website. Here you’ll find information on everything from heart and lung health to important health checks and tips for cutting down on alcohol.
What are your experiences of hypotension? Do you have any other useful tips for managing low blood pressure? We’d be interested to hear from you in the comments below.
